Comparing Measurements of Vascular Diameter Using Adaptative Optics Imaging and Conventional Fundus Imaging

The aim of this prospective study was to compare retinal vascular diameter measurements taken from standard fundus images and adaptive optics (AO) images. We analysed retinal images of twenty healthy subjects with 45-degree funduscopic colour photographs (CR-2 Canon fundus camera, Canon™) and adaptive optics (AO) fundus images (rtx1 camera, Imagine Eyes(®)). Diameters were measured using three software applications: the VAMPIRE (Vessel Assessment and Measurement Platform for Images of the REtina) annotation tool, IVAN (Interactive Vessel ANalyzer) for funduscopic colour photographs, and AO_Detect_Artery™ for AO images. For the arterial diameters, the mean difference between AO_Detect_Artery™ and IVAN was 9.1 µm (−27.4 to 9.2 µm, p = 0.005) and the measurements were significantly correlated (r = 0.79). The mean difference between AO_Detect_Artery™ and VAMPIRE annotation tool was 3.8 µm (−34.4 to 26.8 µm, p = 0.16) and the measurements were poorly correlated (r = 0.12). For the venous diameters, the mean difference between the AO_Detect_Artery™ and IVAN was 3.9 µm (−40.9 to 41.9 µm, p = 0.35) and the measurements were highly correlated (r = 0.83). The mean difference between the AO_Detect_Artery™ and VAMPIRE annotation tool was 0.4 µm (−17.44 to 25.3 µm, p = 0.91) and the correlations were moderate (r = 0.41). We found that the VAMPIRE annotation tool, an entirely manual software, is accurate for the measurement of arterial and venular diameters, but the correlation with AO measurements is poor. On the contrary, IVAN, a semi-automatic software tool, presents slightly greater differences with AO imaging, but the correlation is stronger. Data from arteries should be considered with caution, since IVAN seems to significantly under-estimate arterial diameters

Retinal Vessel Phenotype In Patients With Primary Open-Angle Glaucoma

International audiencePURPOSE: To characterize the phenotype of retinal vessels using central retinal artery equivalent (CRAE), central retinal vein equivalent (CRVE), tortuosity and fractal dimension (FD) in primary open-angle glaucoma (POAG) subjects. METHODS: This prospective case-control multicentre study included 61 POAG subjects and 61 controls matched for age, systemic hypertension and body mass index. Fundus images of the right eye were acquired using a non-mydriatic camera. Central retinal artery equivalent (CRAE), CRVE, arteriole-to-venule ratio, FD and tortuosity of the vascular network were measured using VAMPIRE software (Vessel Assessment and Measurement Platform for Images of the Retina). Primary open-angle glaucoma (POAG) patients underwent 24.2 sita-standard visual field and peri-papillary optical coherence tomography (OCT) examinations. Data were expressed as median and interquartile range (75-25th percentiles). RESULTS: The control group was comparable to the POAG group for sex ratio, refraction and intraocular pressure. The mean CRAE and the mean CRVE were significantly lower in the POAG group than in the control group [150.5 (137.9; 157.1) mum versus 161.3 (154.0; 168.4) mum and 204.8 (190.1; 218.1) mum versus 233.5 (222.3; 246.9) mum, respectively; p < 0.001] and for fractal parameters as well. No significant difference was found for tortuosity between the two groups. There was a significant correlation between CRAE and retinal nerve fibre layer (RNFL) thickness (r = 0.27; p = 0.03). VAMPIRE parameters were not correlated with visual field indices. CONCLUSION: Primary open-angle glaucoma (POAG) was associated with a narrowing of arterial and venous retinal vessels, a higher arteriole-to-venule ratio and lower values of FD. The relationship between CRAE and RNFL thickness needs further investigation

Innovative Formulation Combining Al, Zr and Si Precursors to Obtain Anticorrosion Hybrid Sol-Gel Coating

The aim of our study is to improve the aluminium alloy corrosion resistance with Organic-Inorganic Hybrid (OIH) sol-gel coating. Coatings are obtained from unusual formulation with precursors mixing: glycidoxypropyltrimethoxysilane (GPTMS), zirconium (IV) propoxide (TPOZ) and aluminium tri-sec-butoxide (ASB). This formulation was characterized and compared with sol formulations GPTMS/TPOZ and GPTMS/ASB. In each formulation, a corrosion inhibitor, cerium (III) nitrate hexahydrate, is employed to improve the corrosion performance. Coatings obtained from sol based on GPTMS/TPOZ/ASB have good anti-corrosion performances with Natural Salt Spray (NSS) resistance of 500 h for a thickness lower than 4 µm. Contact angle measurement showed a coating hydrophobic behaviour. To understand these performances, nuclear magnetic resonance (NMR) analyses were performed, results make sol-gel coating condensation evident and are in very good agreement with previous results

‘Knock on nanocellulose’: Approaching the laminar burning velocity of powder-air flames

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Nanocellulose explosions: influence of the agglomeration and turbulence on the combustion rate-limiting step and flame propagation

Dust explosion risk assessment is relatively well established for micron-sized particles and requires the determination of key safety parameters representing the ignition sensitivity and explosion severity of the dust. When considering nanoparticles, the particle size distribution (PSD) is more likely to vary during the injection process, due to both the agglomeration phenomenon inherent to strong interactions and the fragmentation phenomenon due to flow shear stresses. As a consequence, safety parameters and their determination methods can differ significantly from micro to nanopowders. A peculiar attention has then to be given to the cloud characteristics (PSD, turbulence), more precisely at the exact moment of ignition. This work focuses on nanocellulose and aims at evaluating the influence of the agglomeration phenomenon and flow turbulence on the dust combustion. Flame propagation tests were performed to evaluate the unstretched burning velocity and explosions tests were carried out to estimate the combustion mechanisms involved

Conception et optimisation d’un nouveau contact Ethernet 10 Gbits/s pour environnement sévère

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Behavior of nurses and nurse aides toward influenza vaccine: the impact of the perception of occupational working conditions

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Case report: Antenatal diagnostic of a polymalformative syndrome due to biallelic BRCA2 mutations

International audienceTesting the partner of a BRCA2 carrier must always be discussed. If both members of the couple are BRCA2 carriers, they should be informed about the high risks of polymalformative syndromes

Caractérisation électrique en hautes fréquences à 4 GHz par une méthode en cavité résonante de matériaux polymères

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Modélisation, caractérisation et optimisation d'un contact Ethernet 10 Gbits/s

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