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Functional near-infrared spectroscopy

Rebecca Re, Edoardo Martinenghi, Alberto Dalla Mora, Davide Contini, Antonio Pifferi, Alessandro Torricelli
We report the development of a compact probe for time-domain (TD) functional near-infrared spectroscopy (fNIRS) based on a fast silicon photomultiplier (SiPM) that can be put directly in contact with the sample without the need of optical fibers for light collection. We directly integrated an avalanche signal amplification stage close to the SiPM, thus reducing the size of the detection channel and optimizing the signal immunity to electromagnetic interferences. The whole detection electronics was placed in a plastic screw holder compatible with the electroencephalography standard cap for measurement on brain or with custom probe holders...
October 2016: Neurophotonics
Lin Li, Mary Cazzell, Olajide Babawale, Hanli Liu
Atlas-guided diffuse optical tomography (atlas-DOT) is a computational means to image changes in cortical hemodynamic signals during human brain activities. Graph theory analysis (GTA) is a network analysis tool commonly used in functional neuroimaging to study brain networks. Atlas-DOT has not been analyzed with GTA to derive large-scale brain connectivity/networks based on near-infrared spectroscopy (NIRS) measurements. We introduced an automated voxel classification (AVC) method that facilitated the use of GTA with atlas-DOT images by grouping unequal-sized finite element voxels into anatomically meaningful regions of interest within the human brain...
October 2016: Neurophotonics
Kana Iwakuni, Sho Okubo, Koichi M T Yamada, Hajime Inaba, Atsushi Onae, Feng-Lei Hong, Hiroyuki Sasada
We demonstrate that dual-comb spectroscopy, which allows one to record broadband spectra with high frequency accuracy in a relatively short time, provides a real advantage for the observation of pressure-broadening and pressure-shift effects. We illustrate this with the ν_{1}+ν_{3} vibration band of ^{12}C_{2}H_{2}. We observe transitions from P(26) to R(29), which extend over a 3.8 THz frequency range, at six pressures ranging up to 2654 Pa. Each observed absorption line profile is fitted to a Voigt function yielding pressure-broadening and pressure-shift coefficients for each rotation-vibration transition...
September 30, 2016: Physical Review Letters
Filippo Molinari, Daniele Rimini, William Liboni, U Rajendra Acharya, Marianno Franzini, Sergio Pandolfi, Giovanni Ricevuti, Francesco Vaiano, Luigi Valdenassi, Vincenzo Simonetti
Ozone major autohemotherapy is effective in reducing the symptoms of multiple sclerosis (MS) patients, but its effects on brain are still not clear. In this work, we have monitored the changes in the cerebrovascular pattern of MS patients and normal subjects during major ozone autohemotherapy by using near-infrared spectroscopy (NIRS) as functional and vascular technique. NIRS signals are analyzed using a combination of time, time-frequency analysis and nonlinear analysis of intrinsic mode function signals obtained from empirical mode decomposition technique...
October 12, 2016: Medical & Biological Engineering & Computing
Jiapeng Hou, Deepak H Veeregowda, Joop de Vries, Henny C Van der Mei, Henk J Busscher
Water-based lubrication provides cheap and environmentally friendly lubrication and, although hydrophilic surfaces are preferred in water-based lubrication, often lubricating surfaces do not retain water molecules during shear. We show here that hydrophilic (42° water contact angle) quartz surfaces facilitate water-based lubrication to the same extent as more hydrophobic Si crystal surfaces (61°), while lubrication by hydrophilic Ge crystal surfaces (44°) is best. Thus surface hydrophilicity is not sufficient for water-based lubrication...
October 2016: Journal of the Royal Society, Interface
Eric A Muller, Benjamin Pollard, Hans A Bechtel, Peter van Blerkom, Markus B Raschke
Molecular solids and polymers can form low-symmetry crystal structures that exhibit anisotropic electron and ion mobility in engineered devices or biological systems. The distribution of molecular orientation and disorder then controls the macroscopic material response, yet it is difficult to image with conventional techniques on the nanoscale. We demonstrated a new form of optical nanocrystallography that combines scattering-type scanning near-field optical microscopy with both optical antenna and tip-selective infrared vibrational spectroscopy...
October 2016: Science Advances
Christian Herff, Tanja Schultz
Speech interfaces have become widely accepted and are nowadays integrated in various real-life applications and devices. They have become a part of our daily life. However, speech interfaces presume the ability to produce intelligible speech, which might be impossible due to either loud environments, bothering bystanders or incapabilities to produce speech (i.e., patients suffering from locked-in syndrome). For these reasons it would be highly desirable to not speak but to simply envision oneself to say words or sentences...
2016: Frontiers in Neuroscience
Zhenhu Liang, Yue Gu, Xuejing Duan, Lei Cheng, Shujuan Liang, Yunjie Tong, Xiaoli Li
Monitoring the changes of cerebral hemodynamics and the state of consciousness during general anesthesia (GA) is clinically important. There is a great need for developing advanced detectors to investigate the physiological processes of the brain during GA. We developed a multichanneled, functional near-infrared spectroscopy (fNIRS) system device and applied it to GA operation monitoring. The cerebral hemodynamic data from the forehead of 11 patients undergoing propofol and sevoflurane anesthesia were analyzed...
October 2016: Neurophotonics
Noman Naseer, Nauman Khalid Qureshi, Farzan Majeed Noori, Keum-Shik Hong
We analyse and compare the classification accuracies of six different classifiers for a two-class mental task (mental arithmetic and rest) using functional near-infrared spectroscopy (fNIRS) signals. The signals of the mental arithmetic and rest tasks from the prefrontal cortex region of the brain for seven healthy subjects were acquired using a multichannel continuous-wave imaging system. After removal of the physiological noises, six features were extracted from the oxygenated hemoglobin (HbO) signals. Two- and three-dimensional combinations of those features were used for classification of mental tasks...
2016: Computational Intelligence and Neuroscience
Konstantina Dipla, Areti Triantafyllou, Iris Grigoriadou, Evangelia Kintiraki, Georgios A Triantafyllou, Pavlos Poulios, Ioannis S Vrabas, Andreas Zafeiridis, Stella Douma, Dimitrios G Goulis
AIMS/HYPOTHESIS: Gestational diabetes mellitus (GDM) is a risk factor for the development of endothelial dysfunction and cardiovascular disease. However, in vivo microvascular endothelial function in GDM has not been investigated. This study aimed to examine, using near-infrared spectroscopy (NIRS), whether: (1) there are differences in microvascular reactivity and skeletal muscle oxygen consumption (m[Formula: see text]) at rest and during exercise between GDM and uncomplicated pregnancies; and (2) there is an association of NIRS indices with macrovascular function and cardiovascular disease risk factors...
October 8, 2016: Diabetologia
Kristof Vandekerckhove, Ilse Coomans, Annelies Moerman, Daniel De Wolf, Jan Boone
AIMS: To characterize the oxygenation responses at cerebral and locomotor muscle level to incremental exercise in children and to assess the interrelationship with the pulmonary gas exchange responses. METHODS: Eighteen children (9 boys, 9 girls) (mean age 10.9 ± 1.0 years) performed incremental cycle ramp exercise to exhaustion. The concentration of cerebral and muscle oxygenated (O2Hb) and deoxygenated (HHb) hemoglobin (by means of near-infrared spectroscopy) and pulmonary gas exchange was recorded...
October 6, 2016: European Journal of Applied Physiology
Guifei Zhou, Jiangang Liu, Xiao Pan Ding, Genyue Fu, Kang Lee
Numerous developmental studies have suggested that other-race effect (ORE) in face recognition emerges as early as in infancy and develops steadily throughout childhood. However, there is very limited research on the neural mechanisms underlying this developmental ORE. The present study used Granger causality analysis (GCA) to examine the development of children's cortical networks in processing own- and other-race faces. Children were between 3 and 13 years. An old-new paradigm was used to assess their own- and other-race face recognition with ETG-4000 (Hitachi Medical Co...
2016: Frontiers in Human Neuroscience
Young-A Lee, Valentine Pollet, Akemi Kato, Yukiori Goto
In biomedical research of brain dysfunction in psychiatric disorders, utilization of animal models is essential. However, translation of findings in animal models into the realm of human clinical conditions requires reliable biomarkers that are assessed with the methods mutually employed in animal models and human patients. Near-infrared spectroscopy (NIRS) is a functional neuroimaging technique that has now been widely utilized in human basic and clinical research. However, its application to animal models has been barely conducted...
October 1, 2016: Behavioural Brain Research
James R Hemmer, Saemi O Poelma, Nicolas Treat, Zachariah A Page, Neil Dolinski, Yvonne J Diaz, Warren Tomlinson, Kyle D Clark, Joseph P Hooper, Craig J Hawker, Javier Read de Alaniz
A class of tunable visible and near-infrared donor-acceptor Stenhouse adduct (DASA) photoswitches were efficiently synthesized in 2 to 4 steps from commercially available starting materials with minimal purification. Using either Meldrum's or barbituric acid "acceptors" in combination with aniline-based "donors" an absorption range spanning from 450 to 750 nm is obtained. Additionally, photoisomerization results in complete decoloration for all adducts, yielding fully transparent, colorless solutions and films...
October 4, 2016: Journal of the American Chemical Society
Yafeng Pan, Xiaojun Cheng, Zhenxin Zhang, Xianchun Li, Yi Hu
This study investigated interactive exchange in lovers and the associated interpersonal brain synchronization (IBS) using functional near-infrared spectroscopy (fNIRS)-based hyperscanning. Three types of female-male dyads, lovers, friends, and strangers, performed a cooperation task during which brain activity was recorded in right frontoparietal regions. We measured better cooperative behavior in lover dyads compared with friend and stranger dyads. Lover dyads demonstrated increased IBS in right superior frontal cortex, which also covaried with their task performance...
October 4, 2016: Human Brain Mapping
Hoang-Dung Nguyen, Keum-Shik Hong
The paper presents a functional near-infrared spectroscopy (fNIRS)-based bundled-optode method for detection of the changes of oxy-hemoglobin (HbO) and deoxy-hemoglobin (HbR) concentrations. fNIRS with 32 optodes is utilized to measure five healthy male subjects' brain-hemodynamic responses to arithmetic tasks. Specifically, the coordinates of 256 voxels in the three-dimensional (3D) volume are computed according to the known probe geometry. The mean path length factor in the Beer-Lambert equation is estimated as a function of the emitter-detector distance, which is utilized for computation of the absorption coefficient...
September 1, 2016: Biomedical Optics Express
Hellmuth Obrig, Julia Mock, Franziska Stephan, Maria Richter, Micol Vignotto, Sonja Rossi
During early language development native phonotactics are acquired in a 'bottom-up' fashion, relying on exquisite auditory differentiation skills operational from birth. Since basic lexico-semantic abilities have been demonstrated from 6 months onwards, 'top-down' influences on phonotactic learning may complement the extraction of transitional probabilities in phonotactic learning. Such a bidirectional acquisition strategy predicts, that familiarization with (proto)words should affect processing of untrained word-forms of similar phonological structure...
September 20, 2016: Developmental Cognitive Neuroscience
Martin J Herrmann, Dorothea Neueder, Anna K Troeller, Stefan M Schulz
Emotional processing is probably the most crucial tool for orienting oneself in our everyday social life and has been considered to be highly automatic for a long time. Dual task (DT) research shows that information competing for working memory resources impairs the identification of emotional facial expressions. Effects of cognitive load in DT paradigms have been confirmed in numerous neuroimaging studies. However, interference occurring during a DT comprised of decoding emotional facial expressions and a visuo-spatial working memory task has yet to be visualized...
September 25, 2016: International Journal of Psychophysiology
Pardis Kaynezhad, Ilias Tachtsidis, Glen Jeffery
Mitochondria play a key role in ageing and disease. Their membrane potentials and ATP production decline with age and this is associated with progressive inflammation, cell loss and death. Here we use broadband Near-Infrared Spectroscopy (NIRS) to non-invasively measure in-vivo changes in aged retinal mitochondrial respiration following exposure to 670 nm, which improves mitochondrial performance and reduces inflammation. Low power NIR light was shone into the eye via a fibre optic and the reflection monitored to measure signature changes in the oxidation of cytochrome c oxidase (COX) in complex IV of the electron transport chain...
September 21, 2016: Experimental Eye Research
M B Johansson, P T Kristiansen, L Duda, G A Niklasson, L Österlund
Nanocrystalline tungsten trioxide (WO3) thin films prepared by DC magnetron sputtering have been studied using soft x-ray spectroscopy and optical spectrophotometry. Resonant inelastic x-ray scattering (RIXS) measurements reveal band gap states in sub-stoichiometric γ-WO3-x with x  =  0.001-0.005. The energy positions of these states are in good agreement with recently reported density functional calculations. The results were compared with optical absorption measurements in the near infrared spectral region...
November 30, 2016: Journal of Physics. Condensed Matter: An Institute of Physics Journal
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