Search results for "Near Infrared"

Subcutaneous Veins Depth Estimation Method Using Monte Carlo Simulations

2015

International audience; Subcutaneous veins localization is basic and important step for any intravenous medication administration. Due to different physiological characteristics, mainly darker skin tone, scars or dehydrated condition of patients, medical staff face difficulty in veins localization. Through near infrared imaging technology the veins can be visualized due to high contrast between veins and skin tissue in this modality. Information on the depth of veins is equally important for proper catheterization or venipuncture procedures. Patients have different veins depth due to the different amount of fat present in the subcutaneous layer. The depth of veins from the skin surface cann…

Extraction and fusion of spectral parameters for face recognition

2011

This is the copy of journal's version originally published in Proc. SPIE 7877: http://spie.org/x10.xml?WT.svl=tn7. Reprinted with permission of SPIE. Many methods have been developed in image processing for face recognition, especially in recent years with the increase of biometric technologies. However, most of these techniques are used on grayscale images acquired in the visible range of the electromagnetic spectrum. The aims of our study are to improve existing tools and to develop new methods for face recognition. The techniques used take advantage of the different spectral ranges, the visible, optical infrared and thermal infrared, by either combining them or analyzing them separately …

Development of functionalizable azaBODIPYs for the conception of theranostic agents and bimodal probes for imaging uses

2020

The in vivo use of optical imaging is still limited by the lack of near infrared emitting probes. This thesis work focuses on the optimization and valorization of a water-soluble fluorescent platform whose optical properties enable an in vivo use. Two distinct applications were investigated for this WazaBY (Water-soluble azaBODIPY) platform: use as a PET (or SPECT) / optical bimodal probe, and as a theranostic agent. Concerning the first project, we were able to develop a targetted SPECT/optical bimodal probe, which was radiometallated with indium 111. Using xenografted murine models, we were able to show a clear accumulation of the probe in the tumor 24 hours after injection. Moreover, the…

Diagnostic Validity of Digital Imaging Fiber-Optic Transillumination (DIFOTI) and Near-Infrared Light Transillumination (NILT) for Caries in Dentine.

2020

The objective of the study is to analyse the available evidence for the validity of the transillumination method in the diagnosis of interproximal caries. Bibliographic searches were carried out in three data bases (PubMed, Embase, Scopus) with the key words “Transillumination AND caries”. A total of 11 studies were selected for the qualitative analysis and meta-analysis. In the qualitative analysis, both in vivo and in vitro studies were included. The gold standards were tomography, digital radiography, and clinical visual diagnosis. The meta-analysis determined the sensitivity, specificity, and area below the ROC curve relative to the transillumination method in the diagnosis …

Modulation of hippocampal neurogenesis by Nano-Pulsed Laser Therapy

Neurogenesis is a physiological process through which new neurons are generated and it occurs throughout life, subverting the old dogma stating to the inability of the adult brain to replace neurons. Specifically, neurogenesis take place thanks to the presence of neuronal stem cells (NSCs) located in the subventricular zone of the lateral ventricle and in the subgranular zone of the dentate gyrus of the hippocampus. Data present in the literature demonstrate that neurogenesis in the hippocampus decreases during aging and it is impaired in neurodegenerative diseases, such as Alzheimer’s disease, and after traumatic brain injury (TBI). Traumatic Brain Injury (TBI) is a chronic disease that oc…

Lost in Transition: A Systematic Review of Neonatal Electroencephalography in the Delivery Room—Are We Forgetting an Important Biomarker for Newborn …

2017

Background: Electroencephalography (EEG) monitoring is routine in neonatal intensive care units (NICU) for detection of seizures, neurological monitoring of infants following perinatal asphyxia, and increasingly, following preterm delivery. EEG monitoring is not routinely commenced in the delivery room (DR). Objectives: To determine the feasibility of recording neonatal EEG in the DR, and to assess its usefulness as a marker of neurological wellbeing during immediate newborn transition. Methods: We performed a systematic stepwise search of PubMed using the following terms: infant, newborns, neonate, delivery room, afterbirth, transition and electroencephalography. Only human studies describ…

Characterization of pre-treatments on wood chips prior to delignification by near infrared spectroscopy

2017

A near infrared (NIR) spectroscopy-based method for predicting yields and lignin contents of differently pre-treated silver/white birch (Betula pendula/B. pubescens) and Scots pine (Pinus sylvestris) chips was developed. The approach was to create multivariate calibration models from the NIR data by the partial least squares (PLS) method. Both parameters are important factors when adjusting adequate conditions for pre-treatments either with hot-water (HW) as such and slightly acidified HW (collectively referred to as autohydrolysis) or dilute alkaline aqueous solutions prior to alkaline pulping. Pre-treatment conditions were varied with respect to temperature (130 °C and 150 °C) and treatme…

The Nature of Rest Silanol Groups on the Surfaces of Silica Based Solid Phase Extraction Materials

2013

Author's version of an article in the journal: Advanced Materials Research. Also available from the publisher at: http://dx.doi.org/10.4028/www.scientific.net/AMR.650.66 Chemically bonded solid phase materials are very important in separation chemistry. The chemically modified silica gel contains rest silanol groups that can affect the retention properties when they are used for separation of compounds. Some commercially available solid phase extraction (SPE) materials based on silica gel were analysed for rest silanol groups by near infrared spectroscopy. The combination frequency of the water molecules in the 5500- 5000 cm -1 region was used in identifying the nature of water molecules on…

Prototyping algorithm for retrieving FAPAR using MSG data in the context of the LSA SAF project

2007

This paper describes the prototyping algorithm developed for retrieving the Fraction of Absorbed Photosynthetically Active Radiation (FAPAR) using MSG data in the framework of satellite application facility on land surface analysis (LSA SAF). The prototyping relies on the Roujean and Breon (1995) method, which is based on simulations of visible and near infrared reflectance values in an optimal geometry. A relationship is found between a vegetation index and daily FAPAR The algorithm has been applied to one year of MSG BRDF data since August 2005, using a temporal frequency of 5-days, and then validated against a set of operational satellite FAPAR products such as MODIS, MERIS, SeaWiFS and …

Optimization criteria in sample selection step of local regression for quantitative analysis of large soil NIRS database

2012

International audience; Large soil spectral libraries compiling thousands of NIR (Near Infrared) reflectance spectra have been created encompassing a wide diversity and heterogeneity of spectra. Among the many chemometric approaches to the calibration of chemical and physical properties from these large libraries, local calibrations have the advantage of being able to select the most similar spectra to the spectrum of a target sample. This is particularly relevant when dealing with highly heterogeneous media such as soils, where the mineral matrix has a strong influence on spectral features. A crucial step in the implementation of local calibration procedures is the construction of local ne…