scholarly journals 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 ◽  
Vol 16 (6) ◽  
pp. e0253323
Author(s):  
Mário L. R. Monteiro ◽  
Rafael M. Sousa ◽  
Rafael B. Araújo ◽  
Daniel Ferraz ◽  
Mohammad A. Sadiq ◽  
...  
Keyword(s):  
Optic Atrophy ◽  
Near Infrared ◽  
Screening Method ◽  
Fundus Photography ◽  
Infrared Reflectance ◽  
Near Infrared Reflectance ◽  
Chiasmal Compression ◽  
Fundus Imaging ◽  
Cell Layers ◽  
Level Of Agreement

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. VF loss was estimated and retinal layers thickness were measured on OCT. Two examiners blinded to the diagnosis randomly examined NIR images for the presence of hyporeflective abnormality (HA) and OCT scans for the presence of microcystic macular abnormalities (MMA). The total average and hemi-macular HA area and number of microcysts were determined. The groups were compared and the level of agreement was estimated. Results The OCT-measured macular retinal nerve fiber and ganglion cell layers were thinner and the inner nuclear layer was thicker in patients compared to controls. HA and MMA were detected in 22 and 12 patient eyes, respectively, and in 0 controls (p<0.001, both comparisons). HA was significantly more frequent than MMA in patients with optic atrophy, and agreement between HA and MMA (both total and hemi-macular) was fair (kappa range: 0.24–0.29). The mean HA area was significantly greater in the nasal than temporal hemi-macula. A re-analysis of the 14 eyes with discrepant findings allowed to confirm RMM in 20 eyes (20/34) indicating that OCT detected RMM in 12 and missed it in 8 eyes. On the other hand, NIR correctly detected 18 out of 20 eyes, overcalled 4 and missed 2. Conclusions RMM is a frequent finding in eyes with severe VF loss from long-standing chiasmal compression. NIR photography appears to be more sensitive than OCT for detecting RMM and may be useful as screening method for its presence.

Application of Near Infrared Reflectance Spectroscopy to Compositional Analysis of Commercial Pig Feed Mixes

1987 ◽  
Vol 70 (3) ◽  
pp. 420-423
Author(s):  
Shih-Ling Y Chen ◽  
Ali Hsu ◽  
Mane-Lane Lee
Keyword(s):  
Near Infrared ◽  
Screening Method ◽  
Compositional Analysis ◽  
Correlation Coefficients ◽  
Reflectance Spectroscopy ◽  
Infrared Reflectance ◽  
Near Infrared Reflectance Spectroscopy ◽  
Near Infrared Reflectance ◽  
Infrared Reflectance Spectroscopy ◽  
Pig Feed

Abstract Official samples of commercial pig feed mixes taken for routine inspection were analyzed by near infrared reflectance spectroscopy (NIRS). Separate calibrations were established for pre-starting pig, starting pig, growing pig, finishing pig, and lactating sow feeds. Mean correlation coefficients and standard errors of calibration, respectively, obtained by comparing NIRS values with conventional chemical analysis values, were as follows: calibration set (about 35 samples per category)-moisture 0.87,0.44%; protein 0.90,0.75%; fiber 0.8b, 0.49%; analytical set (about 15 samples per category)—moisture 0.73, 0.42%; protein 0.90, 0.72%; fiber 0.83, 0.40%. Mean coefficients of variation for NIRS were moisture 3.9%, protein 4.2%, and fiber 14.8%; those for conventional analyses were moisture 2.7%, protein 1.1%, and fiber 11.7%. The results indicated that for moisture, protein, and fiber determinations in commercial pig feed mix products with various and unknown formulations, successful rapid NIRS analysis could be achieved by using a filter-type spectrometer and advanced mathematical data treatments. Among 246 samples inspected, protein content in 70% of them exceeded by 1-8% the legal minimum protein level. Application of NIRS provides an accurate and prompt on-line technique for feed mix analysis during the formulation process and can be beneficial to the operation of feed mills. For official inspection, the technique might serve as a preliminary screening method.

Severe COVID-19 and Retina: Are There Any Retinal Manifestations?

2021 ◽  
Author(s):  
Medine Gündogan ◽  
Soner Kiliç ◽  
Sertan Göktas ◽  
Esra Vural ◽  
Muhammed Rasit Sirem ◽  
...  
Keyword(s):  
Near Infrared ◽  
Fundus Autofluorescence ◽  
Fundus Photography ◽  
Systemic Diseases ◽  
Infrared Reflectance ◽  
Cotton Wool ◽  
Near Infrared Reflectance ◽  
Cotton Wool Spots ◽  
The Mean ◽  
Oct Imaging

Abstract Purpose To investigate whether there are retinal lesions associated with severe COVID-19. Methods We studied 232 symptomatic subjects aged 18 – 65 years who had severe COVID-19 and had received treatment. The evaluations included ophthalmological examinations, optical coherence tomography (OCT), imaging modalities with near infrared reflectance (NIR), fundus autofluorescence (FAF), and fundus photography (FP). Results The mean age of the patients was 49 years, and 67.6% of them were men. There were no findings of microhemorrhage, cotton wool spots (CWS), vitritis, or retinitis in the examination and imaging. Conclusions This study indicates that retinal involvement as a complication associated with COVID-19 is questionable, although some reports have demonstrated a relationship that may occur secondary to existing systemic diseases.

scholarly journals Predicting quality, texture and chemical content of yam (Dioscorea alata L.) tubers using near infrared spectroscopy

2021 ◽  
pp. 096703352110075
Author(s):  
Adou Emmanuel Ehounou ◽  
Denis Cornet ◽  
Lucienne Desfontaines ◽  
Carine Marie-Magdeleine ◽  
Erick Maledon ◽  
...  
Keyword(s):  
High Throughput ◽  
Dry Matter ◽  
Near Infrared ◽  
Reflectance Spectroscopy ◽  
Infrared Reflectance ◽  
Quality Traits ◽  
Near Infrared Reflectance Spectroscopy ◽  
Near Infrared Reflectance ◽  
Infrared Reflectance Spectroscopy ◽  
Texture Attributes

Despite the importance of yam ( Dioscorea spp.) tuber quality traits, and more precisely texture attributes, high-throughput screening methods for varietal selection are still lacking. This study sets out to define the profile of good quality pounded yam and provide screening tools based on predictive models using near infrared reflectance spectroscopy. Seventy-four out of 216 studied samples proved to be moldable, i.e. suitable for pounded yam. While samples with low dry matter (<25%), high sugar (>4%) and high protein (>6%) contents, low hardness (<5 N), high springiness (>0.5) and high cohesiveness (>0.5) grouped mostly non-moldable genotypes, the opposite was not true. This outline definition of a desirable chemotype may allow breeders to choose screening thresholds to support their choice. Moreover, traditional near infrared reflectance spectroscopy quantitative prediction models provided good prediction for chemical aspects (R2 > 0.85 for dry matter, starch, protein and sugar content), but not for texture attributes (R2 < 0.58). Conversely, convolutional neural network classification models enabled good qualitative prediction for all texture parameters but hardness (i.e. an accuracy of 80, 95, 100 and 55%, respectively, for moldability, cohesiveness, springiness and hardness). This study demonstrated the usefulness of near infrared reflectance spectroscopy as a high-throughput way of phenotyping pounded yam quality. Altogether, these results allow for an efficient screening toolbox for quality traits in yams.

scholarly journals Climate predicts both visible and near‐infrared reflectance in butterflies

2021 ◽  
Author(s):  
Changku Kang ◽  
Sehyeok Im ◽  
Won Young Lee ◽  
Yunji Choi ◽  
Devi Stuart‐Fox ◽  
...  
Keyword(s):  
Near Infrared ◽  
Infrared Reflectance ◽  
Near Infrared Reflectance

scholarly journals One-Pot Hydrothermal Synthesis of Victoria Green (Ca3Cr2Si3O12) Nanoparticles in Alkaline Fluids and Its Colour Hue Characterisation

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 521
Author(s):  
Juan Carlos Rendón-Angeles ◽  
Zully Matamoros-Veloza ◽  
Jose Luis Rodríguez-Galicia ◽  
Gimyeong Seong ◽  
Kazumichi Yanagisawa ◽  
...  
Keyword(s):  
Near Infrared ◽  
Single Step ◽  
Spectral Space ◽  
Infrared Reflectance ◽  
Hydrothermal Preparation ◽  
Near Infrared Reflectance ◽  
One Pot ◽  
Factors Affecting ◽  
B Values ◽  
Alkaline Conditions

One-pot hydrothermal preparation of Ca3Cr2Si3O12 uvarovite nanoparticles under alkaline conditions was investigated for the first time. The experimental parameters selected for the study considered the concentration of the KOH solvent solution (0.01 to 5.0 M), the agitation of the autoclave (50 rpm), and the nominal content of Si4+ (2.2–3.0 mole). Fine uvarovite particles were synthesised at 200 °C after a 3 h interval in a highly concentrated 5.0 M KOH solution. The crystallisation of single-phase Ca3Cr2Si3O12 particles proceeded free of by-products via a one-pot process involving a single-step reaction. KOH solutions below 2.5 M and water hindered the crystallisation of the Ca3Cr2Si3O12 particles. The hydrothermal treatments carried out with stirring (50 rpm) and non-stirring triggered the crystallisation of irregular anhedral particles with average sizes of 8.05 and 12.25 nm, respectively. These particles spontaneously assembled into popcorn-shaped agglomerates with sizes varying from 66 to 156 nm. All the powders prepared by the present method exhibited CIE-L*a*b* values that correspond to the Victoria green colour spectral space and have a high near infrared reflectance property. The particle size and structural crystallinity are factors affecting the Victoria pigment optical properties, such as CIE-L*a*b* values, green tonality, and near-infrared reflectance.

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