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Elhusseiny AM, Scarcelli G, Saeedi OJ. Corneal Biomechanical Measures for Glaucoma: A Clinical Approach. Bioengineering (Basel) 2023; 10:1108. [PMID: 37892838 PMCID: PMC10604716 DOI: 10.3390/bioengineering10101108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 09/11/2023] [Accepted: 09/14/2023] [Indexed: 10/29/2023] Open
Abstract
Over the last two decades, there has been growing interest in assessing corneal biomechanics in different diseases, such as keratoconus, glaucoma, and corneal disorders. Given the interaction and structural continuity between the cornea and sclera, evaluating corneal biomechanics may give us further insights into the pathogenesis, diagnosis, progression, and management of glaucoma. Therefore, some authorities have recommended baseline evaluations of corneal biomechanics in all glaucoma and glaucoma suspects patients. Currently, two devices (Ocular Response Analyzer and Corneal Visualization Schiempflug Technology) are commercially available for evaluating corneal biomechanics; however, each device reports different parameters, and there is a weak to moderate agreement between the reported parameters. Studies are further limited by the inclusion of glaucoma subjects taking topical prostaglandin analogues, which may alter corneal biomechanics and contribute to contradicting results, lack of proper stratification of patients, and misinterpretation of the results based on factors that are confounded by intraocular pressure changes. This review aims to summarize the recent evidence on corneal biomechanics in glaucoma patients and insights for future studies to address the current limitations of the literature studying corneal biomechanics.
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Affiliation(s)
- Abdelrahman M. Elhusseiny
- Department of Ophthalmology, Harvey and Bernice Jones Eye Institute, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA;
- Department of Ophthalmology, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Giuliano Scarcelli
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA;
- Department of Ophthalmology and Visual Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Osamah J. Saeedi
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA;
- Department of Ophthalmology and Visual Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA
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2
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Cheburkanov V, Keene E, Pipal J, Johns M, Applegate BE, Yakovlev VV. Porcine vocal fold elasticity evaluation using Brillouin spectroscopy. J Biomed Opt 2023; 28:087002. [PMID: 37560326 PMCID: PMC10407566 DOI: 10.1117/1.jbo.28.8.087002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Revised: 07/18/2023] [Accepted: 07/21/2023] [Indexed: 08/11/2023]
Abstract
Significance The vocal folds are critically important structures within the larynx which serve the essential functions of supporting the airway, preventing aspiration, and phonation. The vocal fold mucosa has a unique multilayered architecture whose layers have discrete viscoelastic properties facilitating sound production. Perturbations in these properties lead to voice loss. Currently, vocal fold pliability is inferred clinically using laryngeal videostroboscopy and no tools are available for in vivo objective assessment. Aim The main objective of the present study is to evaluate viability of Brillouin microspectroscopy for differentiating vocal folds' mechanical properties against surrounding tissues. Approach We used Brillouin microspectroscopy as an emerging optical imaging modality capable of providing information about local viscoelastic properties of tissues in noninvasive and remote manner. Results Brillouin measurements of the porcine larynx vocal folds were performed. Elasticity-driven Brillouin spectral shifts were recorded and analyzed. Elastic properties, as assessed by Brillouin spectroscopy, strongly correlate with those acquired using classical elasticity measurements. Conclusions These results demonstrate the feasibility of Brillouin spectroscopy for vocal fold imaging. With more extensive research, this technique may provide noninvasive objective assessment of vocal fold mucosal pliability toward objective diagnoses and more targeted treatments.
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Affiliation(s)
- Vsevolod Cheburkanov
- Texas A&M University, Department of Biomedical Engineering, College Station, Texas, United States
| | - Ethan Keene
- Texas A&M University, Department of Biomedical Engineering, College Station, Texas, United States
- Tarleton State University, Department of Physics, Stephenville, Texas, United States
| | - Jason Pipal
- Texas A&M University, Department of Biomedical Engineering, College Station, Texas, United States
- Tarleton State University, Department of Physics, Stephenville, Texas, United States
| | - Michael Johns
- University of Southern California, Caruso Department of Otolaryngology–Head and Neck Surgery, Los Angeles, California, United States
| | - Brian E. Applegate
- University of Southern California, Caruso Department of Otolaryngology–Head and Neck Surgery, Los Angeles, California, United States
- University of Southern California, Department of Biomedical Engineering, Los Angeles, California, United States
| | - Vladislav V. Yakovlev
- Texas A&M University, Department of Biomedical Engineering, College Station, Texas, United States
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3
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Rix J, Uckermann O, Kirsche K, Schackert G, Koch E, Kirsch M, Galli R. Correlation of biomechanics and cancer cell phenotype by combined Brillouin and Raman spectroscopy of U87-MG glioblastoma cells. J R Soc Interface 2022; 19:20220209. [PMID: 35857926 DOI: 10.1098/rsif.2022.0209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The elucidation of biomechanics furthers our understanding of brain tumour biology. Brillouin spectroscopy is a new optical method that addresses viscoelastic properties down to subcellular resolution in a contact-free manner. Moreover, it can be combined with Raman spectroscopy to obtain co-localized biochemical information. Here, we applied co-registered Brillouin and Raman spectroscopy to U87-MG human glioblastoma cells in vitro. Using two-dimensional and three-dimensional cultures, we related biomechanical properties to local biochemical composition at the subcellular level, as well as the cell phenotype. Brillouin and Raman mapping of adherent cells showed that the nucleus and nucleoli are stiffer than the perinuclear region and the cytoplasm. The biomechanics of the cell cytoplasm is affected by culturing conditions, i.e. cells grown as spheroids are stiffer than adherent cells. Inside the spheroids, the presence of lipid droplets as assessed by Raman spectroscopy revealed higher Brillouin shifts that are not related to a local increase in stiffness, but are due to a higher refractive index combined with a lower mass density. This highlights the importance of locally defined biochemical reference data for a correct interpretation of the Brillouin shift of cells and tissues in future studies investigating the biomechanics of brain tumour models by Brillouin spectroscopy.
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Affiliation(s)
- Jan Rix
- Clinical Sensoring and Monitoring, Department of Anesthesiology and Intensive Care Medicine, Faculty of Medicine Carl Gustav Carus, TU Dresden, Fetscherstrasse 74, D-01307 Dresden, Germany
| | - Ortrud Uckermann
- Neurosurgery, Faculty of Medicine Carl Gustav Carus, TU Dresden, Fetscherstrasse 74, D-01307 Dresden, Germany.,Division of Medical Biology, Department of Psychiatry, Faculty of Medicine and University Hospital Carl Gustav Carus, TU Dresden, Fetscherstrasse 74, D-01307 Dresden, Germany
| | - Katrin Kirsche
- Neurosurgery, Faculty of Medicine Carl Gustav Carus, TU Dresden, Fetscherstrasse 74, D-01307 Dresden, Germany
| | - Gabriele Schackert
- Neurosurgery, Faculty of Medicine Carl Gustav Carus, TU Dresden, Fetscherstrasse 74, D-01307 Dresden, Germany
| | - Edmund Koch
- Clinical Sensoring and Monitoring, Department of Anesthesiology and Intensive Care Medicine, Faculty of Medicine Carl Gustav Carus, TU Dresden, Fetscherstrasse 74, D-01307 Dresden, Germany
| | - Matthias Kirsch
- Neurosurgery, Faculty of Medicine Carl Gustav Carus, TU Dresden, Fetscherstrasse 74, D-01307 Dresden, Germany.,Klinik für Neurochirurgie, Asklepios Kliniken Schildautal, Karl-Herold-Strasse 1, D-38723 Seesen, Germany.,National Center for Tumor Diseases (NCT), Partner Site Dresden, Fetscherstrasse 74, D-01307 Dresden, Germany
| | - Roberta Galli
- Department of Medical Physics and Biomedical Engineering, Faculty of Medicine Carl Gustav Carus, TU Dresden, Fetscherstrasse 74, D-01307 Dresden, Germany
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4
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Xiang Y, Seow KLC, Paterson C, Török P. Multivariate analysis of Brillouin imaging data by supervised and unsupervised learning. J Biophotonics 2021; 14:e202000508. [PMID: 33675294 DOI: 10.1002/jbio.202000508] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 02/16/2021] [Accepted: 03/03/2021] [Indexed: 06/12/2023]
Abstract
Brillouin imaging relies on the reliable extraction of subtle spectral information from hyperspectral datasets. To date, the mainstream practice has been to use line fitting of spectral features to retrieve the average peak shift and linewidth parameters. Good results, however, depend heavily on sufficient signal-to-noise ratio and may not be applicable in complex samples that consist of spectral mixtures. In this work, we thus propose the use of various multivariate algorithms that can be used to perform supervised or unsupervised analysis of the hyperspectral data, with which we explore advanced image analysis applications, namely unmixing, classification and segmentation in a phantom and live cells. The resulting images are shown to provide more contrast and detail, and obtained on a timescale ∼102 faster than fitting. The estimated spectral parameters are consistent with those calculated from pure fitting.
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Affiliation(s)
- YuChen Xiang
- Blackett Laboratory, Department of Physics, Imperial College London, London, UK
| | - Kai Ling C Seow
- Blackett Laboratory, Department of Physics, Imperial College London, London, UK
| | - Carl Paterson
- Blackett Laboratory, Department of Physics, Imperial College London, London, UK
| | - Peter Török
- Division of Physics and Applied Physics, Nanyang Technological University, Nanyang, Singapore
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5
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Wu Y, Yang C, Pan J, Sui Q, Wang D. Ultrafast Resolution-Enhanced Digital Optical Frequency Comb-Based BOTDA with Pump Pulse Array Coding. Sensors (Basel) 2020; 20:s20226411. [PMID: 33182619 PMCID: PMC7696811 DOI: 10.3390/s20226411] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2020] [Revised: 11/04/2020] [Accepted: 11/04/2020] [Indexed: 11/16/2022]
Abstract
In this letter, a resolution enhancement and signal-to-noise ratio (SNR) improvement scheme for digital optical frequency comb (DOFC)-based Brillouin optical time-domain analysis (BOTDA) ultrafast distributed sensing employing a pump pulse array is proposed. Based on the properties of the time-invariant linear system and the cyclic revolution theorem, experimental results indicate that its spatial resolution reaches 10.24 m while the frequency uncertainty is below 2 MHz over a 9.5 km fiber. Moreover, the response time is only 209.6 μs and the temperature measurement error is less than 0.52 °C.
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Affiliation(s)
- Yichang Wu
- School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China; (Y.W.); (J.P.); (D.W.)
| | - Chengkun Yang
- School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China; (Y.W.); (J.P.); (D.W.)
- Correspondence:
| | - Jingshun Pan
- School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China; (Y.W.); (J.P.); (D.W.)
| | - Qi Sui
- Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519000, China;
| | - Dawei Wang
- School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China; (Y.W.); (J.P.); (D.W.)
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De Santis R, Alfano V, de Turris V, Colantoni A, Santini L, Garone MG, Antonacci G, Peruzzi G, Sudria-Lopez E, Wyler E, Anink JJ, Aronica E, Landthaler M, Pasterkamp RJ, Bozzoni I, Rosa A. Mutant FUS and ELAVL4 (HuD) Aberrant Crosstalk in Amyotrophic Lateral Sclerosis. Cell Rep 2019; 27:3818-3831.e5. [PMID: 31242416 PMCID: PMC6613039 DOI: 10.1016/j.celrep.2019.05.085] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 04/04/2019] [Accepted: 05/22/2019] [Indexed: 12/13/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) has been genetically linked to mutations in RNA-binding proteins (RBPs), including FUS. Here, we report the RNA interactome of wild-type and mutant FUS in human motor neurons (MNs). This analysis identified a number of RNA targets. Whereas the wild-type protein preferentially binds introns, the ALS mutation causes a shift toward 3' UTRs. Neural ELAV-like RBPs are among mutant FUS targets. As a result, ELAVL4 protein levels are increased in mutant MNs. ELAVL4 and mutant FUS interact and co-localize in cytoplasmic speckles with altered biomechanical properties. Upon oxidative stress, ELAVL4 and mutant FUS are engaged in stress granules. In the spinal cord of FUS ALS patients, ELAVL4 represents a neural-specific component of FUS-positive cytoplasmic aggregates, whereas in sporadic patients it co-localizes with phosphorylated TDP-43-positive inclusions. We propose that pathological mutations in FUS trigger an aberrant crosstalk with ELAVL4 with implications for ALS.
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Affiliation(s)
- Riccardo De Santis
- Center for Life Nano Science, Istituto Italiano di Tecnologia, Viale Regina Elena 291, 00161 Rome, Italy; Department of Biology and Biotechnology Charles Darwin, Sapienza University of Rome, P.le A. Moro 5, 00185 Rome, Italy
| | - Vincenzo Alfano
- Department of Biology and Biotechnology Charles Darwin, Sapienza University of Rome, P.le A. Moro 5, 00185 Rome, Italy
| | - Valeria de Turris
- Center for Life Nano Science, Istituto Italiano di Tecnologia, Viale Regina Elena 291, 00161 Rome, Italy
| | - Alessio Colantoni
- Department of Biology and Biotechnology Charles Darwin, Sapienza University of Rome, P.le A. Moro 5, 00185 Rome, Italy
| | - Laura Santini
- Department of Biology and Biotechnology Charles Darwin, Sapienza University of Rome, P.le A. Moro 5, 00185 Rome, Italy
| | - Maria Giovanna Garone
- Department of Biology and Biotechnology Charles Darwin, Sapienza University of Rome, P.le A. Moro 5, 00185 Rome, Italy
| | - Giuseppe Antonacci
- Center for Life Nano Science, Istituto Italiano di Tecnologia, Viale Regina Elena 291, 00161 Rome, Italy
| | - Giovanna Peruzzi
- Center for Life Nano Science, Istituto Italiano di Tecnologia, Viale Regina Elena 291, 00161 Rome, Italy
| | - Emma Sudria-Lopez
- Department of Translational Neuroscience, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht University, Universiteitsweg 100, 3584 CG Utrecht, the Netherlands
| | - Emanuel Wyler
- Berlin Institute for Medical Systems Biology, Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association, Robert-Rössle-Strasse 10, 13125 Berlin, Germany
| | - Jasper J Anink
- Amsterdam UMC, University of Amsterdam, Department of (Neuro)Pathology, Amsterdam Neuroscience, Meibergdreef 9, 1105 AZ Amsterdam, the Netherlands
| | - Eleonora Aronica
- Amsterdam UMC, University of Amsterdam, Department of (Neuro)Pathology, Amsterdam Neuroscience, Meibergdreef 9, 1105 AZ Amsterdam, the Netherlands
| | - Markus Landthaler
- Berlin Institute for Medical Systems Biology, Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association, Robert-Rössle-Strasse 10, 13125 Berlin, Germany; IRI Life Sciences, Institute für Biologie, Humboldt Universität zu Berlin, Philippstraße 13, 10115 Berlin, Germany
| | - R Jeroen Pasterkamp
- Department of Translational Neuroscience, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht University, Universiteitsweg 100, 3584 CG Utrecht, the Netherlands
| | - Irene Bozzoni
- Center for Life Nano Science, Istituto Italiano di Tecnologia, Viale Regina Elena 291, 00161 Rome, Italy; Department of Biology and Biotechnology Charles Darwin, Sapienza University of Rome, P.le A. Moro 5, 00185 Rome, Italy
| | - Alessandro Rosa
- Center for Life Nano Science, Istituto Italiano di Tecnologia, Viale Regina Elena 291, 00161 Rome, Italy; Department of Biology and Biotechnology Charles Darwin, Sapienza University of Rome, P.le A. Moro 5, 00185 Rome, Italy.
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Singaraju AB, Bahl D, Stevens LL. Brillouin Light Scattering: Development of a Near Century-Old Technique for Characterizing the Mechanical Properties of Materials. AAPS PharmSciTech 2019; 20:109. [PMID: 30746575 DOI: 10.1208/s12249-019-1311-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 01/15/2019] [Indexed: 11/30/2022] Open
Abstract
Brillouin light scattering (BLS), a technique theoretically described nearly a century back by the French physicist Léon Brillouin in 1922, is a light-scattering method for determining the mechanical properties of materials. This inelastic scattering method is described by the Bragg diffraction of light from a propagating fluctuation in the local dielectric. These fluctuations arise spontaneously from thermally populated sound waves intrinsic to all materials, and thus BLS may be broadly applied to transparent samples of any phase. This review begins with a brief historical overview of the development of BLS, from its theoretical prediction to the current state of the art, and notes specific technological advancements that enabled the development of BLS. Despite the broad utility of BLS, no commercial spectrometer is currently available for purchase, but rather individual components are assembled to suit a specific application. Central to any BLS spectrometer is the interferometer, and its performance characteristics-scanning or non-scanning, multi-passing, and stabilization-are critical considerations for spectrometer design. Consistent with any light-scattering method, the frequency shift is a key observable in BLS, and we summarize the connection of this measurement to evaluate the mechanical properties of materials. With emphasis toward pharmaceutical materials analysis, we introduce the traditional BLS approach for single-crystal elasticity, and this is followed by a discussion of more recent developments in powder BLS. We conclude our review with a perspective on future developments in BLS that may enable BLS as a novel addition to the current catalog of process analytical technologies.
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8
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Brown JM. Determination of elastic moduli from measured acoustic velocities. Ultrasonics 2018; 90:23-31. [PMID: 29906713 DOI: 10.1016/j.ultras.2018.05.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 05/29/2018] [Accepted: 05/31/2018] [Indexed: 06/08/2023]
Abstract
Methods are evaluated in solution of the inverse problem associated with determination of elastic moduli for crystals of arbitrary symmetry from elastic wave velocities measured in many crystallographic directions. A package of MATLAB functions provides a robust and flexible environment for analysis of ultrasonic, Brillouin, or Impulsive Stimulated Light Scattering datasets. Three inverse algorithms are considered: the gradient-based methods of Levenberg-Marquardt and Backus-Gilbert, and a non-gradient-based (Nelder-Mead) simplex approach. Several data types are considered: body wave velocities alone, surface wave velocities plus a side constraint on X-ray-diffraction-based axes compressibilities, or joint body and surface wave velocities. The numerical algorithms are validated through comparisons with prior published results and through analysis of synthetic datasets. Although all approaches succeed in finding low-misfit solutions, the Levenberg-Marquardt method consistently demonstrates effectiveness and computational efficiency. However, linearized gradient-based methods, when applied to a strongly non-linear problem, may not adequately converge to the global minimum. The simplex method, while slower, is less susceptible to being trapped in local misfit minima. A "multi-start" strategy (initiate searches from more than one initial guess) provides better assurance that global minima have been located. Numerical estimates of parameter uncertainties based on Monte Carlo simulations are compared to formal uncertainties based on covariance calculations.
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Affiliation(s)
- J Michael Brown
- Earth and Space Sciences, University of Washington, Seattle, WA 98195, United States.
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9
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Seiler TG, Shao P, Frueh BE, Yun SH, Seiler T. The influence of hydration on different mechanical moduli of the cornea. Graefes Arch Clin Exp Ophthalmol 2018; 256:1653-1660. [PMID: 30043266 DOI: 10.1007/s00417-018-4069-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 06/13/2018] [Accepted: 07/12/2018] [Indexed: 11/28/2022] Open
Abstract
PURPOSE To determine the interrelation of different elastic moduli of the cornea and to investigate their dependency on corneal hydration. METHODS Rabbit eyes were divided into four groups. Corneas were excised and mounted into a Barron artificial anterior chamber. Various corneal hydration steady states were achieved with different dextran T-500 concentrations in the anterior chamber, as well as on the corneal anterior surface. The treatment-solutions of each group contained either 5, 10, 15, or 20% w/w dextran. Ultrasound pachymetry was used to measure central corneal thickness. Brillouin microscopy of the central cornea determined the longitudinal bulk modulus by means of Brillouin frequency shift. Subsequently, a 5-mm-wide central strip was taken for extensiometry to measure the tangential elastic modulus. RESULTS The longitudinal bulk modulus was 1.2-times higher in corneas dehydrated with 20% dextran compared to those hydrated with 5% dextran. In contrast, the tangential elastic modulus increased by 4.4 times. The obtained longitudinal bulk moduli were two orders of magnitude bigger than the tangential elastic moduli. Regression analysis of longitudinal bulk modulus and tangential elastic modulus revealed a quadratic relation. The bulk modulus seemed to be independent of tension, whereas the elastic modulus was tension-dependent. Greater corneal hydration led to significantly thicker pachymetry. CONCLUSION Corneal biomechanics are highly dependent on the level of corneal hydration. Surprisingly, tangential elastic moduli were more sensitive to hydration changes than longitudinal bulk moduli. A quadratic relation was found between both moduli.
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Affiliation(s)
- Theo G Seiler
- Wellman Center for Photomedicine - Massachusetts General Hospital, Harvard Medical School, Harvard University, 50 Blossom Street, Boston, MA, 02114, USA. .,Universitätsklinik für Augenheilkunde, Inselspital, 3010, Bern, Switzerland. .,Institut für Refraktive und Ophthalmo-Chirurgie (IROC), Stockerstrasse 37, 8002 Zürich, Switzerland, .
| | - Peng Shao
- Wellman Center for Photomedicine - Massachusetts General Hospital, Harvard Medical School, Harvard University, 50 Blossom Street, Boston, MA, 02114, USA
| | - Beatrice E Frueh
- Universitätsklinik für Augenheilkunde, Inselspital, 3010, Bern, Switzerland
| | - Seok-Hyun Yun
- Wellman Center for Photomedicine - Massachusetts General Hospital, Harvard Medical School, Harvard University, 50 Blossom Street, Boston, MA, 02114, USA
| | - Theo Seiler
- Institut für Refraktive und Ophthalmo-Chirurgie (IROC), Stockerstrasse 37, 8002 Zürich, Switzerland
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Zheng H, Fang Z, Wang Z, Lu B, Cao Y, Ye Q, Qu R, Cai H. Brillouin Frequency Shift of Fiber Distributed Sensors Extracted from Noisy Signals by Quadratic Fitting. Sensors (Basel) 2018; 18:s18020409. [PMID: 29385052 PMCID: PMC5855488 DOI: 10.3390/s18020409] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 01/23/2018] [Accepted: 01/29/2018] [Indexed: 11/16/2022]
Abstract
It is a basic task in Brillouin distributed fiber sensors to extract the peak frequency of the scattering spectrum, since the peak frequency shift gives information on the fiber temperature and strain changes. Because of high-level noise, quadratic fitting is often used in the data processing. Formulas of the dependence of the minimum detectable Brillouin frequency shift (BFS) on the signal-to-noise ratio (SNR) and frequency step have been presented in publications, but in different expressions. A detailed deduction of new formulas of BFS variance and its average is given in this paper, showing especially their dependences on the data range used in fitting, including its length and its center respective to the real spectral peak. The theoretical analyses are experimentally verified. It is shown that the center of the data range has a direct impact on the accuracy of the extracted BFS. We propose and demonstrate an iterative fitting method to mitigate such effects and improve the accuracy of BFS measurement. The different expressions of BFS variances presented in previous papers are explained and discussed.
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Affiliation(s)
- Hanrong Zheng
- Shanghai Key Laboratory of All Solid-State Laser and Applied Techniques, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China.
- University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Zujie Fang
- Shanghai Key Laboratory of All Solid-State Laser and Applied Techniques, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China.
| | - Zhaoyong Wang
- Shanghai Key Laboratory of All Solid-State Laser and Applied Techniques, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China.
| | - Bin Lu
- Shanghai Key Laboratory of All Solid-State Laser and Applied Techniques, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China.
- University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Yulong Cao
- Nanjing Pioneer Lasersensing, Nanjing 210019, China.
| | - Qing Ye
- Shanghai Key Laboratory of All Solid-State Laser and Applied Techniques, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China.
| | - Ronghui Qu
- Shanghai Key Laboratory of All Solid-State Laser and Applied Techniques, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China.
| | - Haiwen Cai
- Shanghai Key Laboratory of All Solid-State Laser and Applied Techniques, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China.
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11
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Delepine-Lesoille S, Girard S, Landolt M, Bertrand J, Planes I, Boukenter A, Marin E, Humbert G, Leparmentier S, Auguste JL, Ouerdane Y. France's State of the Art Distributed Optical Fibre Sensors Qualified for the Monitoring of the French Underground Repository for High Level and Intermediate Level Long Lived Radioactive Wastes. Sensors (Basel) 2017; 17:s17061377. [PMID: 28608831 PMCID: PMC5492040 DOI: 10.3390/s17061377] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 04/27/2017] [Accepted: 05/04/2017] [Indexed: 11/16/2022]
Abstract
This paper presents the state of the art distributed sensing systems, based on optical fibres, developed and qualified for the French Cigéo project, the underground repository for high level and intermediate level long-lived radioactive wastes. Four main parameters, namely strain, temperature, radiation and hydrogen concentration are currently investigated by optical fibre sensors, as well as the tolerances of selected technologies to the unique constraints of the Cigéo's severe environment. Using fluorine-doped silica optical fibre surrounded by a carbon layer and polyimide coating, it is possible to exploit its Raman, Brillouin and Rayleigh scattering signatures to achieve the distributed sensing of the temperature and the strain inside the repository cells of radioactive wastes. Regarding the dose measurement, promising solutions are proposed based on Radiation Induced Attenuation (RIA) responses of sensitive fibres such as the P-doped ones. While for hydrogen measurements, the potential of specialty optical fibres with Pd particles embedded in their silica matrix is currently studied for this gas monitoring through its impact on the fibre Brillouin signature evolution.
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Affiliation(s)
| | - Sylvain Girard
- Laboratoire Hubert Curien CNRS UMR 5516, University of Lyon, F-42000 Saint-Etienne, France.
| | - Marcel Landolt
- National Radioactive Waste Management Agency (Andra), F-92298 Chatenay-Malabry, France.
| | - Johan Bertrand
- National Radioactive Waste Management Agency (Andra), F-92298 Chatenay-Malabry, France.
| | - Isabelle Planes
- National Radioactive Waste Management Agency (Andra), F-92298 Chatenay-Malabry, France.
- Laboratoire Hubert Curien CNRS UMR 5516, University of Lyon, F-42000 Saint-Etienne, France.
| | - Aziz Boukenter
- Laboratoire Hubert Curien CNRS UMR 5516, University of Lyon, F-42000 Saint-Etienne, France.
| | - Emmanuel Marin
- Laboratoire Hubert Curien CNRS UMR 5516, University of Lyon, F-42000 Saint-Etienne, France.
| | - Georges Humbert
- XLIM Research Institute, UMR 7252 CNRS/University of Limoges, 123 Avenue Albert Thomas, F-87060, Limoges, France.
| | - Stéphanie Leparmentier
- National Radioactive Waste Management Agency (Andra), F-92298 Chatenay-Malabry, France.
- XLIM Research Institute, UMR 7252 CNRS/University of Limoges, 123 Avenue Albert Thomas, F-87060, Limoges, France.
| | - Jean-Louis Auguste
- XLIM Research Institute, UMR 7252 CNRS/University of Limoges, 123 Avenue Albert Thomas, F-87060, Limoges, France.
| | - Youcef Ouerdane
- Laboratoire Hubert Curien CNRS UMR 5516, University of Lyon, F-42000 Saint-Etienne, France.
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Abstract
Barrett's oesophagus is a condition characterized by a change in the lining of the oesophagus that markedly increases the risk of adenocarcinoma. We demonstrate the first site-matched application of Brillouin microscopy, Raman microscopy and FTIR micro-spectroscopic imaging to ex-vivo epithelial tissue - Barrett's oesophagus. The mechanical and chemical characters of the epithelium were assessed in histological sections from a patient subjected to endoscopic oesophageal biopsy. Previous studies have shown that both these properties change within the oesophageal wall, owing to the presence of distinct cellular and extracellular constituents which are putatively affected by oesophageal cancer. Brillouin microscopy enables maps of elasticity of the epithelium to be obtained, whilst Raman and FTIR imaging provide 'chemical images' without the need for labelling or staining. This site-matched approach provides a valuable platform for investigating the structure, biomechanics and composition of complex heterogeneous systems. A combined Brillouin-Raman device has potential for in-vivo diagnosis of pathology. First application of site-matched micro Brillouin, Raman and FTIR spectroscopic imaging to epithelial tissue in Barrett's oesophagus.
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Affiliation(s)
| | - Marco Madami
- University of Perugia, Department of Physics and Geology, Perugia, I-06100, Italy
| | - Daniele Fioretto
- University of Perugia, Department of Physics and Geology, Perugia, I-06100, Italy
| | | | - Hugh Barr
- Gloucestershire Royal Hospital, Gloucester, GL1 3NN, UK
| | - Antoine David
- University of Exeter, School of Physics, Exeter, EX4 4QL, UK
- ENSEIRB-MATMECA Telecommunications Department, Bordeaux, F-33402, France
| | - Nick Stone
- University of Exeter, School of Physics, Exeter, EX4 4QL, UK.
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13
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Girard A, Gehan H, Crut A, Mermet A, Saviot L, Margueritat J. Mechanical Coupling in Gold Nanoparticles Supermolecules Revealed by Plasmon-Enhanced Ultralow Frequency Raman Spectroscopy. Nano Lett 2016; 16:3843-9. [PMID: 27176093 DOI: 10.1021/acs.nanolett.6b01314] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Acoustic vibrations of assemblies of gold nanoparticles were investigated using ultralow frequency micro-Raman scattering and finite element simulations. When exciting the assemblies resonantly with the surface plasmon resonance of electromagnetically coupled nanoparticles, Raman spectra present an ultralow frequency band whose frequency lies below the lowest Raman active Lamb mode of single nanoparticles that was observed. This feature was ascribed to a Raman vibration mode of gold nanoparticle "supermolecules", that is, nanoparticles mechanically coupled by surrounding polymer molecules. Its measured frequency is inversely proportional to the nanoparticle diameter and sensitive to the elastic properties of the interstitial polymer. The latter dependence as well as finite element simulations suggest that this mode corresponds to the out-of-phase semirigid translation (l = 1 Lamb mode) of each nanoparticle of a dimer inside the matrix, activated by the mechanical coupling between the nanoparticles. These observations were permitted only thanks to the resonant excitation with the coupling plasmon excitation, leading to an enhancement up to 10(4) of the scattering by these vibrations. This enhanced ultralow frequency Raman scattering thus opens a new route to probe the local elastic properties of the surrounding medium.
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Affiliation(s)
- A Girard
- Institut Lumière Matière, Université de Lyon, Université Claude Bernard Lyon 1, UMR CNRS 5306 , 69622 Villeurbanne, France
| | - H Gehan
- Institut Lumière Matière, Université de Lyon, Université Claude Bernard Lyon 1, UMR CNRS 5306 , 69622 Villeurbanne, France
| | - A Crut
- Institut Lumière Matière, Université de Lyon, Université Claude Bernard Lyon 1, UMR CNRS 5306 , 69622 Villeurbanne, France
| | - A Mermet
- Institut Lumière Matière, Université de Lyon, Université Claude Bernard Lyon 1, UMR CNRS 5306 , 69622 Villeurbanne, France
| | - L Saviot
- Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS-Université de Bourgogne Franche Comté , 9 Avenue A. Savary, BP 47 870, F-21078 Dijon Cedex, France
| | - J Margueritat
- Institut Lumière Matière, Université de Lyon, Université Claude Bernard Lyon 1, UMR CNRS 5306 , 69622 Villeurbanne, France
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