3,997 results match your criteria reflectance imaging

Determination of hardness for maize kernels based on hyperspectral imaging.

Food Chem 2021 Jul 8;366:130559. Epub 2021 Jul 8.

College of Engineering, China Agricultural University, NO. 17 Qinghua East Road, Beijing 100083, PR China.

In order to realize rapid and non-destructive detection of hardness for maize kernels, a method for quantitative hardness measurement was proposed based on hyperspectral imaging technology. Firstly, the regression model of hardness and moisture content was established. Then, based on reflectance hyperspectral imaging at wavelengths within 399. Read More

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Optimization of scintillator-reflector optical interfaces for the LUT Davis model.

Med Phys 2021 Jul 20. Epub 2021 Jul 20.

Department of Biomedical Engineering, University of California Davis, Davis, CA, United States of America.

Purpose: Designing and optimizing scintillator-based gamma detector using Monte Carlo simulation is of great importance in nuclear medicine and high energy physics. In scintillation detectors, understanding the light transport in the scintillator and the light collection by the photodetector plays a crucial role in achieving high performance. Thus, accurately modeling them is critical. Read More

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Genetic-algorithm-assisted coherent enhancement absorption in scattering media by exploiting transmission and reflection matrices.

Opt Express 2021 Jun;29(13):20353-20369

The investigations on coherent enhancement absorption (CEA) inside scattering media are critically important in biophotonics. CEA can deliver light to the targeted position, thus enabling deep-tissue optical imaging by improving signal strength and imaging resolution. In this work, we develop a numerical framework that employs the method of finite-difference time-domain. Read More

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Role of multicolour imaging in post-fever retinitis involving posterior pole.

Int Ophthalmol 2021 Jul 14. Epub 2021 Jul 14.

Department of Uveitis and Ocular Immunology, Narayana Nethralaya, Bangalore, India.

Purpose: To describe composite multicolour (MC) imaging features along with the monocoloured fundus reflectance images in active and resolving stages of post-fever retinitis (PFR).

Methods: Retrospective image analysis of cases of PFR who underwent dilated retinal clinical examination followed by optical coherence tomography and MC imaging.

Results: Twenty-five eyes of 18 patients diagnosed with PFR were included. Read More

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Corrigendum: The near-infrared autofluorescence fingerprint of the brain.

J Biophotonics 2021 Jul 14:e202100170. Epub 2021 Jul 14.

Fluorescence Imaging Group, Universidad Autonoma de Madrid, Madrid, Spain.

In the article by J. Lifante et al (doi: 10.1002/jbio. Read More

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Spectral and lifetime resolution of fundus autofluorescence in advanced age-related macular degeneration revealing different signal sources.

Acta Ophthalmol 2021 Jul 13. Epub 2021 Jul 13.

Department of Ophthalmology, University Hospital Jena, Jena, Germany.

Purpose: To determine the fundus autofluorescence (FAF) lifetimes and spectral characteristics of individual drusen and hyperpigmentation independent of those with retinal pigment epithelium (RPE) in geographic atrophy (GA) areas in late-stage age-related macular degeneration (AMD).

Methods: Three consecutive patients with complete RPE and outer retinal atrophy (cRORA) exhibiting drusen that were calcified or associated with hyperpigmentation were investigated with multimodal non-invasive ophthalmic imaging including colour fundus photography (CFP), optical coherence tomography (OCT), near-infrared reflectance (NIR), blue FAF and fluorescence lifetime imaging ophthalmoscopy (FLIO). Fluorescence lifetimes were measured in two spectral channels (short-wavelength spectral channel (SSC): 500-560 nm and long-wavelength spectral channel (LSC): 560-720 nm). Read More

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Artificial Intelligence in Surveillance of Barrett's Esophagus.

Cancer Res 2021 Jul;81(13):3446-3448

University Hospitals Cleveland Medical Center, Cleveland, Ohio.

A study by Waterhouse and colleagues in a previous issue of describes the development and prospective validation of an artificial intelligence approach in conjunction with spectral imaging to enhance endoscopic detection of Barrett's esophagus-related neoplasia. The authors developed a novel spectral endoscope with external optics suitable for routine Barrett's esophagus surveillance with diffuse tissue reflectance to define multispectral data correlated with histopathology. A convolutional neural network was trained on the absis of the spectral signatures acquired as part of a small, prospective clinical trial to distinguish Barrett's esophagus from Barrett's esophagus neoplasia. Read More

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A generalized machine learning approach for dissolved oxygen estimation at multiple spatiotemporal scales using remote sensing.

Environ Pollut 2021 Jul 6;288:117734. Epub 2021 Jul 6.

Environmental Monitoring Central Station of Shenzhen, Shenzhen 518000, China.

Dissolved oxygen (DO) is an effective indicator for water pollution. However, since DO is a non-optically active parameter and has little impact on the spectrum captured by satellite sensors, research on estimating DO by remote sensing at multiple spatiotemporal scales is limited. In this study, the support vector regression (SVR) models were developed and validated using the remote sensing reflectance derived from both Landsat and Moderate Resolution Imaging Spectroradiometer (MODIS) data and synchronous DO measurements (N = 188) and water temperature of Lake Huron and three other inland waterbodies (N = 282) covering latitude between 22-45 °N. Read More

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Automated μFTIR Imaging Demonstrates Taxon-Specific and Selective Uptake of Microplastic by Freshwater Invertebrates.

Environ Sci Technol 2021 Jul 8;55(14):9916-9925. Epub 2021 Jul 8.

Aquatic Ecology and Water Quality Management Group, Wageningen University, Wageningen 6708 PB, The Netherlands.

Microplastic particles can be deposited to sediments and subsequently ingested by benthic organisms. It is unknown to what extent ingestion of microplastic is taxon-specific or whether taxa can be selective toward certain types of microplastics. Here, we used state-of-the-art automated micro-Fourier-transform infrared (μFTIR) imaging and attenuated total reflectance FTIR spectroscopy to determine small-size (20-500 μm) and large-size (500-5000 μm) microplastic particles in sediments and a range of benthic invertebrate species sampled simultaneously from the Dommel River in the Netherlands. Read More

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Optical coherence tomography angiography of choroidal nodules in neurofibromatosis type-1: A case series.

Eur J Ophthalmol 2021 Jul 7:11206721211030781. Epub 2021 Jul 7.

Ophthalmology Department and Health Research Institute (IdISSC), Hospital Clinico San Carlos, Madrid, Spain.

Purpose: To describe optical coherence tomography angiography (OCTA) findings in the retina and choroid of patients with neurofibromatosis type 1 (NF1).

Methods: We describe a series of four patients diagnosed with NF1 and choroidal nodules who underwent a comprehensive ophthalmic evaluation including a retinal multimodal imaging study based on retinography, near-infrared reflectance imaging (NIR), enhanced depth imaging (EDI) optical coherence tomography (OCT) and OCTA.

Results: Patients were three women and one man aged 36-47 years. Read More

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Multimodal imaging as optical biopsy system for gastritis diagnosis in humans, and input of the mouse model.

EBioMedicine 2021 Jul 2;69:103462. Epub 2021 Jul 2.

Université Paris Saclay/UVSQ, INSERM, Infection and Inflammation, UMR 1173, AP-HP, Hôpital Ambroise Paré, Department of Gastroenterology, F92100, Boulogne-Billancourt, France.

Background: Gastric inflammation is a major risk factor for gastric cancer. Current endoscopic methods are not able to efficiently detect and characterize gastric inflammation, leading to a sub-optimal patients' care. New non-invasive methods are needed. Read More

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Applying Hyperspectral Reflectance Imaging to Investigate the Palettes and the Techniques of Painters.

J Vis Exp 2021 Jun 18(172). Epub 2021 Jun 18.

Dipartimento di Scienza dei Materiali, Università degli Studi di Milano-Bicocca.

Reflectance Spectroscopy (RS) and Fiber Optics Reflectance Spectroscopy (FORS) are well-established techniques for the investigation of works of art with particular attention to paintings. Most modern museums put at the disposal of their research groups portable equipment that, together with the intrinsic non-invasiveness of RS and FORS, makes possible the in situ collection of reflectance spectra from the surface of artefacts. The comparison, performed by experts in pigments and painting materials, of the experimental data with databases of reference spectra drives the characterization of the palettes and of the techniques used by the artists. Read More

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High-speed label-free confocal microscopy of with near infrared spectrally encoded confocal microscopy.

Biomed Opt Express 2021 Jun 25;12(6):3607-3618. Epub 2021 May 25.

Mechanical Engineering Department, Lassonde School of Engineering, York University, Toronto, Canada.

() is an optically transparent nematode that shares many gene orthologs and homologs with humans. are widely used in large populations for genetic studies relevant to human biology and disease. Success of such studies frequently relies on the ability to image structure at high-resolution and high-speed. Read More

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Integrated multi-wavelength microscope combining TIRFM and IRM modalities for imaging cellulases and other processive enzymes.

Biomed Opt Express 2021 Jun 11;12(6):3253-3264. Epub 2021 May 11.

Department of Biomedical Engineering, Pennsylvania State University, University Park, PA 16802, USA.

We describe a multimodal microscope for visualizing processive enzymes moving on immobilized substrates. The instrument combines interference reflection microscopy (IRM) with multi-wavelength total internal reflectance fluorescence microscopy (TIRFM). The microscope can localize quantum dots with a precision of 2. Read More

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Sub-millimeter endoscope demonstrates feasibility of in vivo reflectance imaging, fluorescence imaging, and cell collection in the fallopian tubes.

J Biomed Opt 2021 Jul;26(7)

University of Arizona, Department of Biomedical Engineering, Tucson, Arizona, United States.

Significance: Most cases of high-grade serous ovarian carcinoma originate as serous tubal intraepithelial carcinoma (STIC) lesions in the fallopian tube epithelium (FTE), enabling early endoscopic detection.

Aim: The cell-acquiring fallopian endoscope (CAFE) was built to meet requirements for locating potentially pathological tissue indicated by an alteration in autofluorescence or presence of a targeted fluorophore. A channel was included for directed scrape biopsy of cells from regions of interest. Read More

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Assessment of Polymer Atmospheric Correction Algorithm for Hyperspectral Remote Sensing Imagery over Coastal Waters.

Sensors (Basel) 2021 Jun 16;21(12). Epub 2021 Jun 16.

Alfred Wegener Institute, Klußmannstr. 3d, D-27570 Bremerhaven, Germany.

Spaceborne imaging spectroscopy, also called hyperspectral remote sensing, has shown huge potential to improve current water colour retrievals and, thereby, the monitoring of inland and coastal water ecosystems. However, the quality of water colour retrievals strongly depends on successful removal of the atmospheric/surface contributions to the radiance measured by satellite sensors. Atmospheric correction (AC) algorithms are specially designed to handle these effects, but are challenged by the hundreds of narrow spectral bands obtained by hyperspectral sensors. Read More

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Revealing Inflammatory Indications Induced by Titanium Alloy Wear Debris in Periprosthetic Tissue by Label-Free Correlative High-Resolution Ion, Electron and Optical Microspectroscopy.

Materials (Basel) 2021 Jun 3;14(11). Epub 2021 Jun 3.

Department of Orthopaedics, University Medical Centre Maribor, Ljubljanska ulica 5, 2000 Maribor, Slovenia.

The metallic-associated adverse local tissue reactions (ALTR) and events accompanying worn-broken implant materials are still poorly understood on the subcellular and molecular level. Current immunohistochemical techniques lack spatial resolution and chemical sensitivity to investigate causal relations between material and biological response on submicron and even nanoscale. In our study, new insights of titanium alloy debris-tissue interaction were revealed by the implementation of label-free high-resolution correlative microscopy approaches. Read More

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Spatial Scale Effect of a Typical Polarized Remote Sensor on Detecting Ground Objects.

Sensors (Basel) 2021 Jun 28;21(13). Epub 2021 Jun 28.

School of Instrumentation Science & Opto-Electronics Engineering, Beihang University, No. 37 Xueyuan Road, Haidian District, Beijing 100191, China.

For polarized remote sensors, the polarization images of ground objects acquired at different spatial scales will be different due to the spatial heterogeneity of the ground object targets and the limitation of imaging resolution. In this paper, the quantitative inversion problem of a typical polarized remote sensor at different spatial scales was studied. Firstly, the surface roughness of coatings was inversed based on the polarized bidirectional reflectance distribution function (pBRDF) model according to their polarization images at different distances. Read More

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Noninvasive Imaging Methods to Improve the Diagnosis of Oral Carcinoma and Its Precursors: State of the Art and Proposal of a Three-Step Diagnostic Process.

Cancers (Basel) 2021 Jun 8;13(12). Epub 2021 Jun 8.

Multidisciplinary Department of Medical-Surgical and Dental Specialties, University of Campania Luigi Vanvitelli, Via Luigi de Crecchio, 6, 80138 Naples, Italy.

Oral squamous cell carcinoma (OSCC) is the most prevalent form of cancer of lips and oral cavity, and its diagnostic delay, caused by misdiagnosis at the early stages, is responsible for high mortality ratios. Biopsy and histopathological assessment are the gold standards for OSCC diagnosis, but they are time-consuming, invasive, and do not always enable the patient's compliance, mainly in cases of follow-up with the need for more biopsies. The use of adjunctive noninvasive imaging techniques improves the diagnostic approach, making it faster and better accepted by patients. Read More

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Imaging the Retinal Vasculature.

Annu Rev Vis Sci 2021 Jun 25. Epub 2021 Jun 25.

Indiana University School of Optometry, Bloomington, Indiana 47405, USA; email:

Advances in retinal imaging are enabling researchers and clinicians to make precise noninvasive measurements of the retinal vasculature in vivo. This includes measurements of capillary blood flow, the regulation of blood flow, and the delivery of oxygen, as well as mapping of perfused blood vessels. These advances promise to revolutionize our understanding of vascular regulation, as well as the management of retinal vascular diseases. Read More

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Diagnostic ability of confocal near-infrared reflectance fundus imaging to detect retrograde microcystic maculopathy from chiasm compression. A comparative study with OCT findings.

PLoS One 2021 24;16(6):e0253323. Epub 2021 Jun 24.

Byers Eye Institute, Stanford University, Palo Alto, California, United States of America.

Purpose: To evaluate the ability of confocal near-infrared reflectance (NIR) to diagnose retrograde microcystic maculopathy (RMM) in eyes with temporal visual field (VF) loss and optic atrophy from chiasmal compression. To compare NIR findings with optical coherence tomography (OCT) findings in the same group of patients.

Methods: Thirty-four eyes (26 patients) with temporal VF loss from chiasmal compression and 41 healthy eyes (22 controls) underwent NIR fundus photography, and macular OCT scanning. Read More

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Real-time imaging of surface chemical reactions by electrochemical photothermal reflectance microscopy.

Chem Sci 2020 Dec 15;12(5):1930-1936. Epub 2020 Dec 15.

Department of Biomedical Engineering, Department of Electrical & Computer Engineering, Department of Chemistry, Department of Physics, Photonics Center, Boston University Boston MA 02215 USA

Traditional electrochemical measurements based on either current or potential responses only present the average contribution of an entire electrode's surface. Here, we present an electrochemical photothermal reflectance microscope (EPRM) in which a potential-dependent nonlinear photothermal signal is exploited to map an electrochemical process with sub-micron spatial resolution. By using EPRM, we are able to monitor the photothermal signal of a Pt electrode during the electrochemical reaction at an imaging speed of 0. Read More

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December 2020

One-step preparation of antimicrobial silicone materials based on PDMS and salicylic acid: insights from spatially and temporally resolved techniques.

NPJ Biofilms Microbiomes 2021 Jun 21;7(1):51. Epub 2021 Jun 21.

Open Innovation Hub for Antimicrobial Surfaces, Department of Chemistry, University of Liverpool & National Biofilm Innovation Centre, Liverpool, UK.

In this work, we introduce a one-step strategy that is suitable for continuous flow manufacturing of antimicrobial PDMS materials. The process is based on the intrinsic capacity of PDMS to react to certain organic solvents, which enables the incorporation of antimicrobial actives such as salicylic acid (SA), which has been approved for use in humans within pharmaceutical products. By combining different spectroscopic and imaging techniques, we show that the surface properties of PDMS remain unaffected while high doses of the SA are loaded inside the PDMS matrix. Read More

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A copolymer-in-oil tissue-mimicking material with tuneable acoustic and optical characteristics for photoacoustic imaging phantoms.

IEEE Trans Med Imaging 2021 Jun 21;PP. Epub 2021 Jun 21.

Photoacoustic imaging (PAI) standardisation demands a stable, highly reproducible physical phantom to enable routine quality control and robust performance evaluation. To address this need, we have optimised a low-cost copolymer-in-oil tissue-mimicking material formulation. The base material consists of mineral oil, copolymer and stabiliser with defined Chemical Abstract Service numbers. Read More

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Noninvasive in vivo imaging of oral mucosa: state-of-the-art.

Minerva Dent Oral Sci 2021 Jun 15. Epub 2021 Jun 15.

Multidisciplinary Department of Medical Surgical and Dental Specialties, University of Campania Luigi Vanvitelli, Naples, Italy.

Technological development has interested most of the dentistry's branches leading to the use of other medical technologies non previously involved in dental practice. This study aims to evaluate the potential role of non-invasive imaging techniques in oral pathology workflow. Optical coherence tomography has been described by several authors as a promising aid for differential diagnosis of autoimmune diseases and to detect epithelial subversion of the oral mucosa before the clinical manifestation of oral mucositis. Read More

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Skin strata delineation in reflectance confocal microscopy images using recurrent convolutional networks with attention.

Sci Rep 2021 Jun 15;11(1):12576. Epub 2021 Jun 15.

Memorial Sloan Kettering Cancer Center, New York, NY, 10022, USA.

Reflectance confocal microscopy (RCM) is an effective non-invasive tool for cancer diagnosis. However, acquiring and reading RCM images requires extensive training and experience, and novice clinicians exhibit high discordance in diagnostic accuracy. Quantitative tools to standardize image acquisition could reduce both required training and diagnostic variability. Read More

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Shaping the Color and Angular Appearance of Plasmonic Metasurfaces with Tailored Disorder.

ACS Nano 2021 Jun 11;15(6):10318-10327. Epub 2021 Jun 11.

4th Physics Institute and Research Center SCoPE, University of Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany.

The optical properties of plasmonic nanoparticle ensembles are determined not only by the particle shape and size but also by the nanoantenna arrangement. To investigate the influence of the spatial ordering on the far-field optical properties of nanoparticle ensembles, we introduce a disorder model that encompasses both "frozen-phonon" and correlated disorder. We present experimental as well as computational approaches to gain a better understanding of the impact of disorder. Read More

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Trends in utilization of reflectance confocal microscopy in the United States, 2017-2019.

J Am Acad Dermatol 2021 Jun 1. Epub 2021 Jun 1.

Department of Dermatology, University of Connecticut Health Center, Farmington, Connecticut. Electronic address:

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Calibration of a Hyper-Spectral Imaging System Using a Low-Cost Reference.

Sensors (Basel) 2021 May 27;21(11). Epub 2021 May 27.

Department of Engineering Sciences and Mathematics, Luleå University of Technology, 971 87 Luleå, Sweden.

In this paper, we present a hyper-spectral imaging system and practical calibration procedure using a low-cost calibration reference made of polytetrafluoroethylene. The imaging system includes a hyperspectral camera and an active source of illumination with a variable spectral distribution of intensity. The calibration reference is used to measure the relative reflectance of any material surface independent of the spectral distribution of light and camera sensitivity. Read More

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Extraction of the Structural Properties of Skin Tissue via Diffuse Reflectance Spectroscopy: An Inverse Methodology.

Sensors (Basel) 2021 May 28;21(11). Epub 2021 May 28.

State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University, Xi'an 710049, China.

For the laser treatment of vascular dermatosis, the blood vessel morphology and depth in skin tissue is essential to achieve personalized intelligent therapy. The morphology can be obtained from the laser speckle imaging, and vessel depth was extracted by an inverse methodology based on diffuse reflectance spectrum. With optimized spot size of 0. Read More

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