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Ávila FJ, Bueno JM. Spherical Aberration and Scattering Compensation in Microscopy Images through a Blind Deconvolution Method. J Imaging 2024; 10:43. [PMID: 38392091 PMCID: PMC10890253 DOI: 10.3390/jimaging10020043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 01/24/2024] [Accepted: 02/04/2024] [Indexed: 02/24/2024] Open
Abstract
The optical quality of an image depends on both the optical properties of the imaging system and the physical properties of the medium the light passes while travelling from the object to the image plane. The computation of the point spread function (PSF) associated to the optical system is often used to assess the image quality. In a non-ideal optical system, the PSF is affected by aberrations that distort the final image. Moreover, in the presence of turbid media, the scattering phenomena spread the light at wide angular distributions that contribute to reduce contrast and sharpness. If the mathematical degradation operator affecting the recorded image is known, the image can be restored through deconvolution methods. In some scenarios, no (or partial) information on the PSF is available. In those cases, blind deconvolution approaches arise as useful solutions for image restoration. In this work, a new blind deconvolution method is proposed to restore images using spherical aberration (SA) and scatter-based kernel filters. The procedure was evaluated in different microscopy images. The results show the capability of the algorithm to detect both degradation coefficients (i.e., SA and scattering) and to restore images without information on the real PSF.
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Affiliation(s)
- Francisco J Ávila
- Departamento de Física Aplicada, Facultad de Ciencias, Universidad de Zaragoza, 50009 Zaragoza, Spain
| | - Juan M Bueno
- Laboratorio de Óptica, Instituto Universitario de Investigación en Óptica y Nanofísica, Universidad de Murcia, 30100 Murcia, Spain
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2
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Hong M, Chong SZ, Goh YY, Tong L. Two-Photon and Multiphoton Microscopy in Anterior Segment Diseases of the Eye. Int J Mol Sci 2024; 25:1670. [PMID: 38338948 PMCID: PMC10855705 DOI: 10.3390/ijms25031670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2023] [Revised: 01/19/2024] [Accepted: 01/23/2024] [Indexed: 02/12/2024] Open
Abstract
Two-photon excitation microscopy (TPM) and multiphoton fluorescence microscopy (MPM) are advanced forms of intravital high-resolution functional microscopy techniques that allow for the imaging of dynamic molecular processes and resolve features of the biological tissues of interest. Due to the cornea's optical properties and the uniquely accessible position of the globe, it is possible to image cells and tissues longitudinally to investigate ocular surface physiology and disease. MPM can also be used for the in vitro investigation of biological processes and drug kinetics in ocular tissues. In corneal immunology, performed via the use of TPM, cells thought to be intraepithelial dendritic cells are found to resemble tissue-resident memory T cells, and reporter mice with labeled plasmacytoid dendritic cells are imaged to understand the protective antiviral defenses of the eye. In mice with limbal progenitor cells labeled by reporters, the kinetics and localization of corneal epithelial replenishment are evaluated to advance stem cell biology. In studies of the conjunctiva and sclera, the use of such imaging together with second harmonic generation allows for the delineation of matrix wound healing, especially following glaucoma surgery. In conclusion, these imaging models play a pivotal role in the progress of ocular surface science and translational research.
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Affiliation(s)
- Merrelynn Hong
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore;
- Training and Education Department, Singapore National Eye Centre, Singapore 168751, Singapore
| | - Shu Zhen Chong
- Singapore Immunology Network (SIgN), Agency for Science Technology and Research (A*STAR), Singapore 138632, Singapore;
| | - Yun Yao Goh
- Lee Kong Chian School of Medicine, National Technical University, Singapore 639798, Singapore;
| | - Louis Tong
- Corneal and External Diseases Department, Singapore National Eye Centre, Singapore 168751, Singapore
- Ocular Surface Group, Singapore Eye Research Institute, Singapore 169856, Singapore
- Eye Academic Clinical Program, Duke-NUS Medical School, Singapore 169857, Singapore
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3
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Kaushik V, Dąbrowski M, Gessa L, Kumar N, Fernandes H. Two-photon excitation fluorescence in ophthalmology: safety and improved imaging for functional diagnostics. Front Med (Lausanne) 2024; 10:1293640. [PMID: 38235268 PMCID: PMC10791900 DOI: 10.3389/fmed.2023.1293640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 12/11/2023] [Indexed: 01/19/2024] Open
Abstract
Two-photon excitation fluorescence (TPEF) is emerging as a powerful imaging technique with superior penetration power in scattering media, allowing for functional imaging of biological tissues at a subcellular level. TPEF is commonly used in cancer diagnostics, as it enables the direct observation of metabolism within living cells. The technique is now widely used in various medical fields, including ophthalmology. The eye is a complex and delicate organ with multiple layers of different cell types and tissues. Although this structure is ideal for visual perception, it generates aberrations in TPEF eye imaging. However, adaptive optics can now compensate for these aberrations, allowing for improved imaging of the eyes of animal models for human diseases. The eye is naturally built to filter out harmful wavelengths, but these wavelengths can be mimicked and thereby utilized in diagnostics via two-photon (2Ph) excitation. Recent advances in laser-source manufacturing have made it possible to minimize the exposure of in vivo measurements within safety, while achieving sufficient signals to detect for functional images, making TPEF a viable option for human application. This review explores recent advances in wavefront-distortion correction in animal models and the safety of use of TPEF on human subjects, both of which make TPEF a potentially powerful tool for ophthalmological diagnostics.
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Affiliation(s)
- Vineeta Kaushik
- Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland
| | - Michał Dąbrowski
- Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland
- International Centre for Translational Eye Research, Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland
| | - Luca Gessa
- International Centre for Translational Eye Research, Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland
| | - Nelam Kumar
- International Centre for Translational Eye Research, Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland
| | - Humberto Fernandes
- International Centre for Translational Eye Research, Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland
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4
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Raoux C, Chessel A, Mahou P, Latour G, Schanne-Klein MC. Unveiling the lamellar structure of the human cornea over its full thickness using polarization-resolved SHG microscopy. LIGHT, SCIENCE & APPLICATIONS 2023; 12:190. [PMID: 37528091 PMCID: PMC10394036 DOI: 10.1038/s41377-023-01224-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 06/22/2023] [Accepted: 07/05/2023] [Indexed: 08/03/2023]
Abstract
A key property of the human cornea is to maintain its curvature and consequently its refraction capability despite daily changes in intraocular pressure. This is closely related to the multiscale structure of the corneal stroma, which consists of 1-3 µm-thick stacked lamellae made of thin collagen fibrils. Nevertheless, the distribution, size, and orientation of these lamellae along the depth of the cornea are poorly characterized up to now. In this study, we use second harmonic generation (SHG) microscopy to visualize the collagen distribution over the full depth of 10 intact and unstained human corneas (500-600 µm thick). We take advantage of the small coherence length in epi-detection to axially resolve the lamellae while maintaining the corneal physiological curvature. Moreover, as raw epi-detected SHG images are spatially homogenous because of the sub-wavelength size of stromal collagen fibrils, we use a polarimetric approach to measure the collagen orientation in every voxel. After a careful validation of this approach, we show that the collagen lamellae (i) are mostly oriented along the inferior-superior axis in the anterior stroma and along the nasal-temporal axis in the posterior stroma, with a gradual shift in between and (ii) exhibit more disorder in the anterior stroma. These results represent the first quantitative characterization of the lamellar structure of the human cornea continuously along its entire thickness with micrometric resolution. It also shows the unique potential of P-SHG microscopy for imaging of collagen distribution in thick dense tissues.
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Affiliation(s)
- Clothilde Raoux
- Laboratory for Optics and Biosciences, Ecole Polytechnique, CNRS, INSERM, Institut Polytechnique de Paris, 91128, Palaiseau, France
| | - Anatole Chessel
- Laboratory for Optics and Biosciences, Ecole Polytechnique, CNRS, INSERM, Institut Polytechnique de Paris, 91128, Palaiseau, France
| | - Pierre Mahou
- Laboratory for Optics and Biosciences, Ecole Polytechnique, CNRS, INSERM, Institut Polytechnique de Paris, 91128, Palaiseau, France
| | - Gaël Latour
- Laboratory for Optics and Biosciences, Ecole Polytechnique, CNRS, INSERM, Institut Polytechnique de Paris, 91128, Palaiseau, France
- Université Paris-Saclay, 91190, Gif-sur-Yvette, France
| | - Marie-Claire Schanne-Klein
- Laboratory for Optics and Biosciences, Ecole Polytechnique, CNRS, INSERM, Institut Polytechnique de Paris, 91128, Palaiseau, France.
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5
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Martínez-Ojeda RM, Mugnier LM, Artal P, Bueno JM. Blind deconvolution of second harmonic microscopy images of the living human eye. BIOMEDICAL OPTICS EXPRESS 2023; 14:2117-2128. [PMID: 37206134 PMCID: PMC10191662 DOI: 10.1364/boe.486989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 03/17/2023] [Accepted: 03/19/2023] [Indexed: 05/21/2023]
Abstract
Second harmonic generation (SHG) imaging microscopy of thick biological tissues is affected by the presence of aberrations and scattering within the sample. Moreover, additional problems, such as uncontrolled movements, appear when imaging in-vivo. Deconvolution methods can be used to overcome these limitations under some conditions. In particular, we present here a technique based on a marginal blind deconvolution approach for improving SHG images obtained in vivo in the human eye (cornea and sclera). Different image quality metrics are used to quantify the attained improvement. Collagen fibers in both cornea and sclera are better visualized and their spatial distributions accurately assessed. This might be a useful tool to better discriminate between healthy and pathological tissues, especially those where changes in collagen distribution occur.
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Affiliation(s)
- Rosa M. Martínez-Ojeda
- Laboratorio de Óptica,
Instituto Universitario de Investigación en
Óptica y Nanofísica, Universidad de
Murcia, Campus de Espinardo (Ed. 34), 30100 Murcia, Spain
| | | | - Pablo Artal
- Laboratorio de Óptica,
Instituto Universitario de Investigación en
Óptica y Nanofísica, Universidad de
Murcia, Campus de Espinardo (Ed. 34), 30100 Murcia, Spain
| | - Juan M. Bueno
- Laboratorio de Óptica,
Instituto Universitario de Investigación en
Óptica y Nanofísica, Universidad de
Murcia, Campus de Espinardo (Ed. 34), 30100 Murcia, Spain
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6
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Shibuya N, Itokazu T, Ueda T, Yamashita T. Intravital Imaging Reveals the Ameliorating Effect of Colchicine in a Photothrombotic Stroke Model via Inhibition of Neutrophil Recruitment. Transl Stroke Res 2023; 14:100-110. [PMID: 35441983 DOI: 10.1007/s12975-022-01022-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 04/12/2022] [Accepted: 04/12/2022] [Indexed: 01/31/2023]
Abstract
Although post-stroke neutrophil recruitment is known to be deleterious to neural tissues in the peri-infarct area, the precise behavior of recruited neutrophils remains elusive. In this study, potential therapeutic agents for modifying neutrophil behavior in the peri-infarct area were explored through intravital imaging of an experimental stroke mouse model. By applying in vivo 2-photon imaging to study a tightly controlled photothrombotic stroke mouse model, we established a highly sensitive and reproducible method for investigating the temporal dynamics of ischemic brain lesions. Taking advantage of this system, we revealed that neutrophil depletion by a neutrophil-specific antibody ameliorated the expansion of the infarct area, confirming the deleterious effect of neutrophils in the peri-infarct cortex. To identify neutrophil-targeted therapeutic approaches, we screened various agents and found that colchicine and an anti-P-selectin antibody were the most effective in inhibiting neutrophil attachment to the vessel wall in the early phase (6 h post-infarction). Interestingly, further investigation in the later phase (16 h post-infarction) revealed that colchicine potently inhibited neutrophil infiltration into the peri-infarct cortex; however, the anti-P-selectin antibody did not. Subsequent analysis revealed that the effect of the anti-P-selectin antibody against neutrophil attachment to the vessel wall was transient and thus insufficient for mitigating neutrophil infiltration. Finally, we revealed that colchicine treatment effectively ameliorated infarct expansion. In conclusion, we have established an intravital strategy to directly investigate pathophysiology in the ischemic border zone, and found that colchicine administration in the acute phase of ischemic stroke is a potential novel therapeutic strategy.
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Affiliation(s)
- Nao Shibuya
- Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Takahide Itokazu
- Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, Suita, Japan.
- Department of Neuro-Medical Science, Graduate School of Medicine, Osaka University, Suita, Japan.
| | - Tsubasa Ueda
- Department of Neuro-Medical Science, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Toshihide Yamashita
- Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, Suita, Japan.
- Department of Neuro-Medical Science, Graduate School of Medicine, Osaka University, Suita, Japan.
- WPI-Immunology Frontier Research Center, Osaka University, Suita, Japan.
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7
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Batista A, Guimarães P, Domingues JP, Quadrado MJ, Morgado AM. Two-Photon Imaging for Non-Invasive Corneal Examination. SENSORS (BASEL, SWITZERLAND) 2022; 22:9699. [PMID: 36560071 PMCID: PMC9783858 DOI: 10.3390/s22249699] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 12/02/2022] [Accepted: 12/04/2022] [Indexed: 06/17/2023]
Abstract
Two-photon imaging (TPI) microscopy, namely, two-photon excited fluorescence (TPEF), fluorescence lifetime imaging (FLIM), and second-harmonic generation (SHG) modalities, has emerged in the past years as a powerful tool for the examination of biological tissues. These modalities rely on different contrast mechanisms and are often used simultaneously to provide complementary information on morphology, metabolism, and structural properties of the imaged tissue. The cornea, being a transparent tissue, rich in collagen and with several cellular layers, is well-suited to be imaged by TPI microscopy. In this review, we discuss the physical principles behind TPI as well as its instrumentation. We also provide an overview of the current advances in TPI instrumentation and image analysis. We describe how TPI can be leveraged to retrieve unique information on the cornea and to complement the information provided by current clinical devices. The present state of corneal TPI is outlined. Finally, we discuss the obstacles that must be overcome and offer perspectives and outlooks to make clinical TPI of the human cornea a reality.
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Affiliation(s)
- Ana Batista
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), University of Coimbra, 3000-548 Coimbra, Portugal
- Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, 3000-548 Coimbra, Portugal
- Department of Physics, Faculty of Science and Technology, University of Coimbra, 3004-516 Coimbra, Portugal
| | - Pedro Guimarães
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), University of Coimbra, 3000-548 Coimbra, Portugal
- Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, 3000-548 Coimbra, Portugal
| | - José Paulo Domingues
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), University of Coimbra, 3000-548 Coimbra, Portugal
- Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, 3000-548 Coimbra, Portugal
- Department of Physics, Faculty of Science and Technology, University of Coimbra, 3004-516 Coimbra, Portugal
| | - Maria João Quadrado
- Department of Ophthalmology, Centro Hospitalar e Universitário de Coimbra, 3004-561 Coimbra, Portugal
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
| | - António Miguel Morgado
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), University of Coimbra, 3000-548 Coimbra, Portugal
- Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, 3000-548 Coimbra, Portugal
- Department of Physics, Faculty of Science and Technology, University of Coimbra, 3004-516 Coimbra, Portugal
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8
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Carmichael-Martins A, Gast TJ, Burns SA, Walker BR, King BJ. Characterization of the human iridocorneal angle in vivo using a custom design goniolens with OCT gonioscopy. BIOMEDICAL OPTICS EXPRESS 2022; 13:4652-4667. [PMID: 36187241 PMCID: PMC9484429 DOI: 10.1364/boe.465317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 07/18/2022] [Accepted: 07/27/2022] [Indexed: 06/16/2023]
Abstract
Intraocular pressure (IOP) is the only modifiable risk factor for glaucoma progression, and many treatments target the trabecular meshwork (TM). Imaging this region in vivo is challenging due to optical limitations of imaging through the cornea at high angles. We propose a gonioscopic OCT approach using a custom goniolens and a commercially available OCT device to improve imaging of the TM, Schlemm's canal (SC) and adjacent structures within the iridocorneal angle (ICA). The goniolens is modified with a plano-convex focusing lens and placed on the eye optically mated with goniogel and aided by a 3D adjustable mount. Gonioscopic OCT volume scans are acquired to image SC. Transverse enface images allowed measurements of SC over a 45° section of the ICA for the first time and revealed locations of SC narrowing. The band of extracanalicular limbal lamina and corneoscleral bands were imaged in most subjects and these bands were confirmed using exterior OCT imaging. The polarization dependence of the visibility of these structures is studied by polarization rotation the OCT beam with a half-wave plate, allowing increased contrast of SC. Gonioscopic OCT has successfully been used to image the human ICA in 3D in vivo. This approach provides more detailed characterization of the TM and SC, enhancing their contrast against their birefringent backgrounds.
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Affiliation(s)
| | - Thomas J. Gast
- School of Optometry, Indiana University, Bloomington, Indiana 47401, USA
| | - Stephen A. Burns
- School of Optometry, Indiana University, Bloomington, Indiana 47401, USA
| | - Brittany R. Walker
- School of Optometry, Indiana University, Bloomington, Indiana 47401, USA
| | - Brett J. King
- School of Optometry, Indiana University, Bloomington, Indiana 47401, USA
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9
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Osorio R, Asady S, Toledano-Osorio M, Toledano M, Bueno JM, Martínez-Ojeda RM, Osorio E. Biomimetic Remineralization of an Extracellular Matrix Collagen Membrane for Bone Regeneration. Polymers (Basel) 2022; 14:polym14163274. [PMID: 36015534 PMCID: PMC9415104 DOI: 10.3390/polym14163274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 08/04/2022] [Accepted: 08/08/2022] [Indexed: 11/16/2022] Open
Abstract
Natural extracellular matrix (ECM) collagen membranes are frequently used for bone regeneration procedures. Some disadvantages, such as rapid degradation and questionable mechanical properties, limit their clinical use. These membranes have a heterologous origin and may proceed from different tissues. Biomineralization is a process in which hydroxyapatite deposits mainly in collagen fibrils of the matrices. However, when this deposition occurs on the ECM, its mechanical properties are increased, facilitating bone regeneration. The objective of the present research is to ascertain if different membranes from distinct origins may undergo biomineralization. Nanomechanical properties, scanning electron (SEM) and multiphoton (MP) microscopy imaging were performed in three commercially available ECMs before and after immersion in simulated body fluid solution for 7 and 21 d. The matrices coming from porcine dermis increased their nanomechanical properties and they showed considerable mineralization after 21 d, as observed in structural changes detected through SEM and MP microscopy. It is hypothesized that the more abundant crosslinking and the presence of elastin fibers within this membrane explains the encountered favorable behavior.
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Affiliation(s)
- Raquel Osorio
- Faculty of Dentistry, University of Granada, Colegio Máximo de Cartuja s/n, 18071 Granada, Spain
| | - Samara Asady
- Faculty of Dentistry, University of Granada, Colegio Máximo de Cartuja s/n, 18071 Granada, Spain
- Medicina Clínica y Salud Pública Programme, University of Granada, 18071 Granada, Spain
| | - Manuel Toledano-Osorio
- Faculty of Dentistry, University of Granada, Colegio Máximo de Cartuja s/n, 18071 Granada, Spain
- Medicina Clínica y Salud Pública Programme, University of Granada, 18071 Granada, Spain
- Correspondence: ; Tel.: +34-958-243-789
| | - Manuel Toledano
- Faculty of Dentistry, University of Granada, Colegio Máximo de Cartuja s/n, 18071 Granada, Spain
| | - Juan M. Bueno
- Laboratorio de Óptica, Instituto Universitario de Investigación en Óptica y Nanofísica, Universidad de Murcia, Campus de Espinardo (Ed. 34), 30100 Murcia, Spain
| | - Rosa M. Martínez-Ojeda
- Laboratorio de Óptica, Instituto Universitario de Investigación en Óptica y Nanofísica, Universidad de Murcia, Campus de Espinardo (Ed. 34), 30100 Murcia, Spain
| | - Estrella Osorio
- Medicina Clínica y Salud Pública Programme, University of Granada, 18071 Granada, Spain
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10
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Shaw PA, Forsyth E, Haseeb F, Yang S, Bradley M, Klausen M. Two-Photon Absorption: An Open Door to the NIR-II Biological Window? Front Chem 2022; 10:921354. [PMID: 35815206 PMCID: PMC9263132 DOI: 10.3389/fchem.2022.921354] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Accepted: 05/04/2022] [Indexed: 11/13/2022] Open
Abstract
The way in which photons travel through biological tissues and subsequently become scattered or absorbed is a key limitation for traditional optical medical imaging techniques using visible light. In contrast, near-infrared wavelengths, in particular those above 1000 nm, penetrate deeper in tissues and undergo less scattering and cause less photo-damage, which describes the so-called “second biological transparency window”. Unfortunately, current dyes and imaging probes have severely limited absorption profiles at such long wavelengths, and molecular engineering of novel NIR-II dyes can be a tedious and unpredictable process, which limits access to this optical window and impedes further developments. Two-photon (2P) absorption not only provides convenient access to this window by doubling the absorption wavelength of dyes, but also increases the possible resolution. This review aims to provide an update on the available 2P instrumentation and 2P luminescent materials available for optical imaging in the NIR-II window.
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11
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Assessment of Ultra-Early-Stage Liver Fibrosis in Human Non-Alcoholic Fatty Liver Disease by Second-Harmonic Generation Microscopy. Int J Mol Sci 2022; 23:ijms23063357. [PMID: 35328778 PMCID: PMC8949080 DOI: 10.3390/ijms23063357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/15/2022] [Accepted: 03/18/2022] [Indexed: 12/10/2022] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) is associated with the chronic progression of fibrosis. In general, the progression of liver fibrosis is determined by a histopathological assessment with a collagen-stained section; however, the ultra-early stage of liver fibrosis is challenging to identify because of the low sensitivity in the collagen-selective staining method. In the present study, we demonstrate the feasibility of second-harmonic generation (SHG) microscopy in the histopathological diagnosis of the liver of NAFLD patients for the quantitative assessment of the ultra-early stage of fibrosis. We investigated four representative NAFLD patients with early stages of fibrosis. SHG microscopy visualised well-matured fibrotic structures and early fibrosis diffusely involving liver tissues, whereas early fibrosis is challenging to be identified by conventional histopathological methods. Furthermore, the SHG emission directionality analysis revealed the maturation of each collagen fibre of each patient. As a result, SHG microscopy is feasible for assessing liver fibrosis on NAFLD patients, including the ultra-early stage of liver fibrosis that is difficult to diagnose by the conventional histopathological method. The assessment method of the ultra-early fibrosis by using SHG microscopy may serve as a crucial means for pathological, clinical, and prognostic diagnosis of NAFLD patients.
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12
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On the Relationship between Corneal Biomechanics, Macrostructure, and Optical Properties. J Imaging 2021; 7:jimaging7120280. [PMID: 34940747 PMCID: PMC8706034 DOI: 10.3390/jimaging7120280] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 12/15/2021] [Accepted: 12/16/2021] [Indexed: 11/16/2022] Open
Abstract
Optical properties of the cornea are responsible for correct vision; the ultrastructure allows optical transparency, and the biomechanical properties govern the shape, elasticity, or stiffness of the cornea, affecting ocular integrity and intraocular pressure. Therefore, the optical aberrations, corneal transparency, structure, and biomechanics play a fundamental role in the optical quality of human vision, ocular health, and refractive surgery outcomes. However, the inter-relationships of those properties are not yet reported at a macroscopic scale within the hierarchical structure of the cornea. This work explores the relationships between the biomechanics, structure, and optical properties (corneal aberrations and optical density) at a macro-structural level of the cornea through dual Placido–Scheimpflug imaging and air-puff tonometry systems in a healthy young adult population. Results showed correlation between optical transparency, corneal macrostructure, and biomechanics, whereas corneal aberrations and in particular spherical terms remained independent. A compensation mechanism for the spherical aberration is proposed through corneal shape and biomechanics.
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13
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Improving Multiphoton Microscopy by Combining Spherical Aberration Patterns and Variable Axicons. PHOTONICS 2021. [DOI: 10.3390/photonics8120573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Multiphoton (MP) microscopy is a well-established method for the non-invasive imaging of biological tissues. However, its optical sectioning capabilities are reduced due to specimen-induced aberrations. Both the manipulation of spherical aberration (SA) and the use of axicons have been reported to be useful techniques to bypass this limitation. We propose the combination of SA patterns and variable axicons to further improve the quality of MP microscopy images. This approach provides enhanced images at different depth locations whose quality is better than those corresponding to the use of SA or axicons separately. Thus, the procedure proposed herein facilitates the visualization of details and increases the depth observable at high resolution.
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14
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Wang Y, Xi L. Chronic cranial window for photoacoustic imaging: a mini review. Vis Comput Ind Biomed Art 2021; 4:15. [PMID: 34037873 PMCID: PMC8155166 DOI: 10.1186/s42492-021-00081-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 04/27/2021] [Indexed: 12/31/2022] Open
Abstract
Photoacoustic (PA) microscopy is being increasingly used to visualize the microcirculation of the brain cortex at the micron level in living rodents. By combining it with long-term cranial window techniques, vasculature can be monitored over a period of days extending to months through a field of view. To fulfill the requirements of long-term in vivo PA imaging, the cranial window must involve a simple and rapid surgical procedure, biological compatibility, and sufficient optical-acoustic transparency, which are major challenges. Recently, several cranial window techniques have been reported for longitudinal PA imaging. Here, the development of chronic cranial windows for PA imaging is reviewed and its technical details are discussed, including window installation, imaging quality, and longitudinal stability.
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Affiliation(s)
- Yongchao Wang
- School of Physics, University of Electronic Science and Technology of China, Chengdu, 610054, Sichuan, China.,Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, 518055, Guangdong, China
| | - Lei Xi
- Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, 518055, Guangdong, China.
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15
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McGlynn E, Nabaei V, Ren E, Galeote‐Checa G, Das R, Curia G, Heidari H. The Future of Neuroscience: Flexible and Wireless Implantable Neural Electronics. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:2002693. [PMID: 34026431 PMCID: PMC8132070 DOI: 10.1002/advs.202002693] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 01/15/2021] [Indexed: 05/04/2023]
Abstract
Neurological diseases are a prevalent cause of global mortality and are of growing concern when considering an ageing global population. Traditional treatments are accompanied by serious side effects including repeated treatment sessions, invasive surgeries, or infections. For example, in the case of deep brain stimulation, large, stiff, and battery powered neural probes recruit thousands of neurons with each pulse, and can invoke a vigorous immune response. This paper presents challenges in engineering and neuroscience in developing miniaturized and biointegrated alternatives, in the form of microelectrode probes. Progress in design and topology of neural implants has shifted the goal post toward highly specific recording and stimulation, targeting small groups of neurons and reducing the foreign body response with biomimetic design principles. Implantable device design recommendations, fabrication techniques, and clinical evaluation of the impact flexible, integrated probes will have on the treatment of neurological disorders are provided in this report. The choice of biocompatible material dictates fabrication techniques as novel methods reduce the complexity of manufacture. Wireless power, the final hurdle to truly implantable neural interfaces, is discussed. These aspects are the driving force behind continued research: significant breakthroughs in any one of these areas will revolutionize the treatment of neurological disorders.
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Affiliation(s)
- Eve McGlynn
- Microelectronics LabJames Watt School of EngineeringUniversity of GlasgowGlasgowG12 8QQUnited Kingdom
| | - Vahid Nabaei
- Microelectronics LabJames Watt School of EngineeringUniversity of GlasgowGlasgowG12 8QQUnited Kingdom
| | - Elisa Ren
- Laboratory of Experimental Electroencephalography and NeurophysiologyDepartment of BiomedicalMetabolic and Neural SciencesUniversity of Modena and Reggio EmiliaModena41125Italy
| | - Gabriel Galeote‐Checa
- Microelectronics LabJames Watt School of EngineeringUniversity of GlasgowGlasgowG12 8QQUnited Kingdom
| | - Rupam Das
- Microelectronics LabJames Watt School of EngineeringUniversity of GlasgowGlasgowG12 8QQUnited Kingdom
| | - Giulia Curia
- Laboratory of Experimental Electroencephalography and NeurophysiologyDepartment of BiomedicalMetabolic and Neural SciencesUniversity of Modena and Reggio EmiliaModena41125Italy
| | - Hadi Heidari
- Microelectronics LabJames Watt School of EngineeringUniversity of GlasgowGlasgowG12 8QQUnited Kingdom
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16
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Merkle CW, Augustin M, Harper DJ, Gesperger J, Lichtenegger A, Eugui P, Garhöfer G, Glösmann M, Baumann B. High-resolution, depth-resolved vascular leakage measurements using contrast-enhanced, correlation-gated optical coherence tomography in mice. BIOMEDICAL OPTICS EXPRESS 2021; 12:1774-1791. [PMID: 33996197 PMCID: PMC8086440 DOI: 10.1364/boe.415227] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 01/22/2021] [Accepted: 01/24/2021] [Indexed: 06/09/2023]
Abstract
Vascular leakage plays a key role in vision-threatening retinal diseases such as diabetic retinopathy and age-related macular degeneration. Fluorescence angiography is the current gold standard for identification of leaky vasculature in vivo, however it lacks depth resolution, providing only 2D images that complicate precise identification and localization of pathological vessels. Optical coherence tomography (OCT) has been widely adopted for clinical ophthalmology due to its high, micron-scale resolution and rapid volumetric scanning capabilities. Nevertheless, OCT cannot currently identify leaky blood vessels. To address this need, we have developed a new method called exogenous contrast-enhanced leakage OCT (ExCEL-OCT) which identifies the diffusion of tracer particles around leaky vasculature following injection of a contrast agent. We apply this method to a mouse model of retinal neovascularization and demonstrate high-resolution 3D vascular leakage measurements in vivo for the first time.
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Affiliation(s)
- Conrad W. Merkle
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Marco Augustin
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Danielle J. Harper
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Johanna Gesperger
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
- Division of Neuropathology and Neurochemistry, Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Antonia Lichtenegger
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Pablo Eugui
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Gerhard Garhöfer
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Martin Glösmann
- Core Facility for Research and Technology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Bernhard Baumann
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
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17
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Bueno JM, Ávila FJ, Lorenzo-Martín E, Gallego-Muñoz P, Carmen Martínez-García M. Assessment of the corneal collagen organization after chemical burn using second harmonic generation microscopy. BIOMEDICAL OPTICS EXPRESS 2021; 12:756-765. [PMID: 33680540 PMCID: PMC7901323 DOI: 10.1364/boe.412819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 12/22/2020] [Indexed: 05/11/2023]
Abstract
The organization of the corneal stoma is modified due to different factors, including pathology, surgery or external damage. Here the changes in the organization of the corneal collagen fibers during natural healing after chemical burn are investigated using second harmonic generation (SHG) imaging. Moreover, the structure tensor (ST) was used as an objective tool for morphological analyses at different time points after burn (up to 6 months). Unlike control corneas that showed a regular distribution, the collagen pattern at 1 month of burn presented a non-organized arrangement. SHG signal levels noticeably decreased and individual fibers were hardly visible. Over time, the healing process led to a progressive re-organization of the fibers that could be quantified through the ST. At 6 months, the stroma distribution reached values similar to those of control eyes and a dominant direction of the fibers re-appeared. The present results show that SHG microscopy imaging combined with the ST method is able to objectively monitor the temporal regeneration of the corneal organization after chemical burn. Future implementations of this approach into clinically adapted devices would help to diagnose and quantify corneal changes, not only due to chemical damages, but also as a result of disease or surgical procedures.
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Affiliation(s)
- Juan M. Bueno
- Laboratorio de Óptica, Instituto Universitario de Investigación en Óptica y Nanofísica, Universidad de Murcia, Campus de Espinardo (Ed. 34), 30100 Murcia, Spain
| | | | - Elvira Lorenzo-Martín
- Dpto. Biología Celular, Histología y Farmacología, Facultad de Medicina, Universidad de Valladolid, 47005 Valladolid, Spain
| | - Patricia Gallego-Muñoz
- Dpto. Biología Celular, Histología y Farmacología, Facultad de Medicina, Universidad de Valladolid, 47005 Valladolid, Spain
| | - M. Carmen Martínez-García
- Dpto. Biología Celular, Histología y Farmacología, Facultad de Medicina, Universidad de Valladolid, 47005 Valladolid, Spain
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18
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Sioufi K, Zheleznyak L, MacRae S, Rocha KM. Femtosecond Lasers in Cornea & Refractive Surgery. Exp Eye Res 2021; 205:108477. [PMID: 33516763 DOI: 10.1016/j.exer.2021.108477] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 01/20/2021] [Accepted: 01/22/2021] [Indexed: 11/18/2022]
Abstract
Since the introduction of femtosecond laser (FS) systems for corneal flap creation in laser-assisted in-situ keratomileusis there have been numerous applications for FS laser in corneal surgery. This manuscript details the utility of FS lasers in corneal surgical procedures including refractive laser surgeries, intracorneal ring segment tunnels, presbyopic treatments, and FS-assisted keratoplasty. We also review the role of FS lasers in diagnostic procedures such as two photon excitation fluorescence and second harmonic generation.
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Affiliation(s)
- Kareem Sioufi
- Storm Eye Institute, Medical University of South Carolina, Charleston, SC, USA
| | | | - Scott MacRae
- Flaum Eye Institute and the Institute of Optics, University of Rochester, Rochester, NY, USA
| | - Karolinne M Rocha
- Storm Eye Institute, Medical University of South Carolina, Charleston, SC, USA.
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19
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Seet LF, Chu SWL, Teng X, Toh LZ, Wong TT. Assessment of progressive alterations in collagen organization in the postoperative conjunctiva by multiphoton microscopy. BIOMEDICAL OPTICS EXPRESS 2020; 11:6495-6515. [PMID: 33282504 PMCID: PMC7687938 DOI: 10.1364/boe.403555] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 09/14/2020] [Accepted: 09/15/2020] [Indexed: 06/12/2023]
Abstract
Glaucoma filtration surgery (GFS) commonly fails due to excessive fibrosis. As collagen structure aberrations is implicated in adverse fibrotic progression, this study aims to uncover collagen organization alterations during postoperative scarring. Via quantitative second harmonic generation/two photon excitation multiphoton imaging, we reveal the scar development and phenotype in the mouse model of conjunctival scarring. We also show that multiphoton imaging corroborated the collagen ultrastructure anomaly characteristic of the SPARC-/- mouse postoperative conjunctiva. These data improve our understanding of postoperative conjunctival scarring and further enhance the utility of this model for the development of anti-fibrotic therapeutics for GFS.
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Affiliation(s)
- Li-Fong Seet
- Ocular Therapeutics and Drug Delivery, Singapore Eye Research Institute, Singapore
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- Duke-NUS Medical School, Singapore
- Co-corresponding authors
| | - Stephanie W L Chu
- Ocular Therapeutics and Drug Delivery, Singapore Eye Research Institute, Singapore
| | | | - Li Zhen Toh
- Ocular Therapeutics and Drug Delivery, Singapore Eye Research Institute, Singapore
| | - Tina T Wong
- Ocular Therapeutics and Drug Delivery, Singapore Eye Research Institute, Singapore
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- Duke-NUS Medical School, Singapore
- Glaucoma Service, Singapore National Eye Centre, Singapore
- Co-corresponding authors
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20
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Lee EJ, Kee HJ, Han JC, Kee C. Evidence-based understanding of disc hemorrhage in glaucoma. Surv Ophthalmol 2020; 66:412-422. [PMID: 32949554 DOI: 10.1016/j.survophthal.2020.09.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 09/04/2020] [Accepted: 09/09/2020] [Indexed: 12/21/2022]
Abstract
Disc hemorrhage is a characteristic finding that is highly associated with glaucoma development or progression. Consequently, the literature commonly designates disc hemorrhage as a "risk factor" for glaucoma progression; however, the exact cause-and-effect relationship or mechanism remains unclear. In this review, we discuss the emerging evidence that disc hemorrhage is a secondary development that follows glaucomatous damage. As our understanding of disc hemorrhage has progressed in recent decades, we suggest the terminology be changed from "risk factor" to "indicator" of ongoing glaucomatous development or progression for a more accurate description, better indication of the clinical implications and, ultimately, a better guide for future research.
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Affiliation(s)
- Eun Jung Lee
- Department of Ophthalmology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Hyun Joo Kee
- Department of Ophthalmology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Jong Chul Han
- Department of Ophthalmology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Changwon Kee
- Department of Ophthalmology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
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21
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Rivilla I, Aparicio B, Bueno JM, Casanova D, Tonnelé C, Freixa Z, Herrero P, Rogero C, Miranda JI, Martínez-Ojeda RM, Monrabal F, Olave B, Schäfer T, Artal P, Nygren D, Cossío FP, Gómez-Cadenas JJ. Fluorescent bicolour sensor for low-background neutrinoless double β decay experiments. Nature 2020; 583:48-54. [PMID: 32572207 DOI: 10.1038/s41586-020-2431-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Accepted: 04/03/2020] [Indexed: 02/08/2023]
Abstract
Observation of the neutrinoless double β decay is the only practical way to establish that neutrinos are their own antiparticles1. Because of the small masses of neutrinos, the lifetime of neutrinoless double β decay is expected to be at least ten orders of magnitude greater than the typical lifetimes of natural radioactive chains, which can mimic the experimental signature of neutrinoless double β decay2. The most robust identification of neutrinoless double β decay requires the definition of a signature signal-such as the observation of the daughter atom in the decay-that cannot be generated by radioactive backgrounds, as well as excellent energy resolution. In particular, the neutrinoless double β decay of 136Xe could be established by detecting the daughter atom, 136Ba2+, in its doubly ionized state3-8. Here we demonstrate an important step towards a 'barium-tagging' experiment, which identifies double β decay through the detection of a single Ba2+ ion. We propose a fluorescent bicolour indicator as the core of a sensor that can detect single Ba2+ ions in a high-pressure xenon gas detector. In a sensor made of a monolayer of such indicators, the Ba2+ dication would be captured by one of the molecules and generate a Ba2+-coordinated species with distinct photophysical properties. The presence of such a single Ba2+-coordinated indicator would be revealed by its response to repeated interrogation with a laser system, enabling the development of a sensor able to detect single Ba2+ ions in high-pressure xenon gas detectors for barium-tagging experiments.
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Affiliation(s)
- Iván Rivilla
- Donostia International Physics Center (DIPC), San Sebastián/Donostia, Spain
| | - Borja Aparicio
- Department of Organic Chemistry I, University of the Basque Country (UPV/EHU), Centro de Innovación en Química Avanzada (ORFEO-CINQA), San Sebastián/Donostia, Spain
| | - Juan M Bueno
- Laboratorio de Óptica (LOUM) & Centro de Investigación en Óptica y Nanofísica (CiOyN), University of Murcia, Murcia, Spain
| | - David Casanova
- Donostia International Physics Center (DIPC), San Sebastián/Donostia, Spain.,Ikerbasque, Basque Foundation for Science, Bilbao, Spain
| | - Claire Tonnelé
- Donostia International Physics Center (DIPC), San Sebastián/Donostia, Spain
| | - Zoraida Freixa
- Ikerbasque, Basque Foundation for Science, Bilbao, Spain.,Department of Applied Chemistry, Faculty of Chemistry, University of the Basque Country (UPV/EHU), San Sebastián/Donostia, Spain
| | - Pablo Herrero
- Donostia International Physics Center (DIPC), San Sebastián/Donostia, Spain
| | - Celia Rogero
- Donostia International Physics Center (DIPC), San Sebastián/Donostia, Spain.,Materials Physics Center CFM (CSIC-UPV/EHU), San Sebastián/Donostia, Spain
| | - José I Miranda
- SGIker NMR Facility, University of the Basque Country (UPV/EHU), San Sebastián/Donostia, Spain
| | - Rosa M Martínez-Ojeda
- Laboratorio de Óptica (LOUM) & Centro de Investigación en Óptica y Nanofísica (CiOyN), University of Murcia, Murcia, Spain
| | - Francesc Monrabal
- Donostia International Physics Center (DIPC), San Sebastián/Donostia, Spain.,Ikerbasque, Basque Foundation for Science, Bilbao, Spain
| | - Beñat Olave
- NanoBioSeparations Group, POLYMAT, University of the Basque Country (UPV/EHU), San Sebastián/Donostia, Spain
| | - Thomas Schäfer
- Ikerbasque, Basque Foundation for Science, Bilbao, Spain.,NanoBioSeparations Group, POLYMAT, University of the Basque Country (UPV/EHU), San Sebastián/Donostia, Spain
| | - Pablo Artal
- Laboratorio de Óptica (LOUM) & Centro de Investigación en Óptica y Nanofísica (CiOyN), University of Murcia, Murcia, Spain
| | - David Nygren
- Department of Physics, University of Texas at Arlington, Arlington, TX, USA
| | - Fernando P Cossío
- Donostia International Physics Center (DIPC), San Sebastián/Donostia, Spain. .,Department of Organic Chemistry I, University of the Basque Country (UPV/EHU), Centro de Innovación en Química Avanzada (ORFEO-CINQA), San Sebastián/Donostia, Spain.
| | - Juan J Gómez-Cadenas
- Donostia International Physics Center (DIPC), San Sebastián/Donostia, Spain. .,Ikerbasque, Basque Foundation for Science, Bilbao, Spain.
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22
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Hong XJJ, Suchand Sandeep CS, Shinoj VK, Aung T, Barathi VA, Baskaran M, Murukeshan VM. Noninvasive and Noncontact Sequential Imaging of the Iridocorneal Angle and the Cornea of the Eye. Transl Vis Sci Technol 2020; 9:1. [PMID: 32821473 PMCID: PMC7401920 DOI: 10.1167/tvst.9.5.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 12/22/2019] [Indexed: 12/26/2022] Open
Abstract
Purpose High-resolution imaging of the critical anatomic structures of the eye, especially of the anterior chamber, in vivo, remains a challenge, even with currently available state-of-the-art medical imaging techniques. This study aims for the noninvasive and noncontact sequential imaging of the iridocorneal angle, especially the trabecular meshwork (TM) and the cornea of the eye in high-resolution using a newly developed imaging platform. Methods Bessel beam scanned light sheet fluorescence microscopy is used to attain high-resolution images of the TM. The ability of the Bessel beam to self-reconstruct around obstacles increases the image contrast at the TM region inside eye by reducing scattering and shadow artifacts. With minimal modifications, the excitation arm of the developed imaging system is adapted for noncontact, high-resolution corneal imaging. Results High-resolution images of the TM structures and cellular-level corneal structures are obtained in ex vivo porcine eyes, and subsequently in New Zealand white rabbit, in vivo. The spatial resolution of the developed system is 2.19 µm and has a noncontact working distance of 20 mm. Conclusions A high-resolution imaging platform for noncontact sequential imaging of the TM and the cornea of the eye is developed. This imaging system is expected to be of potential interest in the evaluation and diagnosis of glaucoma and corneal diseases. Translational Relevance The developed prototype offers the plausibility of in vivo, noncontact, and high-resolution imaging of the iridocorneal angle and cornea of the eye that will aid clinicians in diagnosing open-angle glaucoma and corneal diseases better.
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Affiliation(s)
- Xun Jie Jeesmond Hong
- Centre for Optical and Laser Engineering, School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore
| | - C S Suchand Sandeep
- Centre for Optical and Laser Engineering, School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore.,Singapore Centre for 3D Printing, School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore
| | - V K Shinoj
- Centre for Optical and Laser Engineering, School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore.,Currently with Union Christian College, Department of Physics, Kerala, India
| | - Tin Aung
- Singapore Eye Research Institute (SERI) & Singapore National Eye Center (SNEC), Singapore.,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Veluchamy Amutha Barathi
- Singapore Eye Research Institute (SERI) & Singapore National Eye Center (SNEC), Singapore.,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,The Ophthalmology & Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore
| | - Mani Baskaran
- Singapore Eye Research Institute (SERI) & Singapore National Eye Center (SNEC), Singapore.,The Ophthalmology & Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore
| | - Vadakke Matham Murukeshan
- Centre for Optical and Laser Engineering, School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore
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