Search results for "Near Infrared"

Spotlight on fundus autofluorescence

2018

Ana M Calvo-Maroto,1 Alejandro Cerviño2 1Department of Ophthalmology, Clínica Universidad de Navarra, University of Navarra, Madrid, Spain; 2Optometry Research Group, Department of Optics and Optometry and Vision Sciences, University of Valencia, Valencia, Spain Abstract: Fundus autofluorescence (FAF) imaging is based on the fluorescence from ocular endogenous fluorophores located in the retinal pigment epithelium and choroid, mainly lipofuscin and melanin. It is a noninvasive technique that provides information about the spatial distribution of lipofuscin/melanin and retinal pigment epithelium health status. An overview about the fluorophores responsible for FAF imaging and t…

Near infrared light to promote synaptic resilience to Alzheimer’s Disease neuropathology

Alzheimer’s Disease (AD) is a multifactorial neurodegenerative dementia with no curative therapeutic options. One of the earliest impairments in AD triggering cognitive decline is the synaptic dysfunction induced by the selective targeting and interruption of the synaptic region by the small oligomeric form of amyloid beta (Aβ). Recently, the co-presence of Aβ oligomers (Aβo) and tau oligomers (tau-o) at the synapses has been suggested to exacerbate this dysfunction. Therefore, the development of therapeutics aimed at protecting the synapses from the toxic binding of both proteins at the synapses can preserve synaptic health and cognitive function. With this goal in mind, the present study …

Progettazione e realizzazione di un sistema Continuous Wave fNIRS basato su tecnologia SiPM

Optical techniques represent a suitable tool for in vivo and non-invasive diagnosis of human brain and tissues. Functional Near InfraRed Spectroscopy (fNIRS) is revealing as an emerging neuroimaging technology, since it is safe, relatively inexpensive and little cumbersome. fNIRS relies on the measurement of the oxygen concentration in the blood by means of light beams impinging on the tissues under test. Haemoglobin concentration variations (oxygenated/deoxygenated) can provide very important information on brain activity and allow to discriminate the main brain area involved during tests. Herein, we present the design and development of an innovative solution for a portable continuous wav…

Design of a portable (CW) fNIRS embedded system

2014

Near infrared spectroscopic study on the adsorption of methanol on silica gel

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.650.150 The silanol groups on Silica gel surface are sites for adsorption of polar molecules. Alcohols and other polar molecules are easily adsorbed by forming hydrogen bondings with OH groups on silica gel surface. A study on the adsorption of methanol on silica gel was carried out by using NIR spectroscopy in combination with ssecond derivative techniques. Four of the well characterised silica gel samples were used in this study. Each of the silica gel (0.25g) samples with different surface areas and silanol number was pressed i…

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…

Determination of fatty acids and lipid classes in salmon oil by near infrared spectroscopy

2017

International audience; Near-infrared (NIR) spectroscopy was evaluated as a rapid method for the determination of oleic, palmitic, linoleic and linolenic acids as well as omega-3, omega-6, and to predict polyunsaturated, monounsaturated and saturated fatty acids, together with triacylglycerides, diglycerides, free fatty acids and ergosterol in salmon oil. To do it, Partial Least Squares (PLS) regression models were applied to correlate NIR spectra with aforementioned fatty acids and lipid classes. Results obtained were validated in front of reference procedures based on high performance thin layer and gas chromatography. PLS-NIR has a good predictive capability with relative root mean squar…

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 …

Iron-loaded transferrin (Tf) is detrimental whereas iron-free Tf confers protection against brain ischemia by modifying blood Tf saturation and subse…

2018

Despite transferrin being the main circulating carrier of iron in body fluids, and iron overload conditions being known to worsen stroke outcome through reactive oxygen species (ROS)-induced damage, the contribution of blood transferrin saturation (TSAT) to stroke brain damage is unknown. The objective of this study was to obtain evidence on whether TSAT determines the impact of experimental ischemic stroke on brain damage and whether iron-free transferrin (apotransferrin, ATf)-induced reduction of TSAT is neuroprotective. We found that experimental ischemic stroke promoted an early extravasation of circulating iron-loaded transferrin (holotransferrin, HTf) to the ischemic brain parenchyma.…

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…