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Near-infrared spectroscopy

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https://www.readbyqxmd.com/read/28647868/effects-of-high-altitude-exposure-on-supraspinal-fatigue-and-corticospinal-excitability-and-inhibition
#1
Mathieu Marillier, Pierrick J Arnal, Thibault Le Roux Mallouf, Thomas Rupp, Guillaume Y Millet, Samuel Verges
PURPOSE: While acute hypoxic exposure enhances exercise-induced central fatigue and can alter corticospinal excitability and inhibition, the effect of prolonged hypoxic exposure on these parameters remains to be clarified. We hypothesized that 5 days of altitude exposure would (i) normalize exercise-induced supraspinal fatigue during isolated muscle exercise to sea level (SL) values and (ii) increase corticospinal excitability and inhibition. METHODS: Eleven male subjects performed intermittent isometric elbow flexions at 50% of maximal voluntary contraction to task failure at SL and after 1 (D1) and 5 (D5) days at 4350 m...
June 24, 2017: European Journal of Applied Physiology
https://www.readbyqxmd.com/read/28647588/environmentally-relevant-concentrations-of-al-iii-and-fe-iii-cations-induce-aggregation-of-free-dna-by-complexation-with-phosphate-group
#2
Chao Qin, Fuxing Kang, Wei Zhang, Weijun Shou, Xiaojie Hu, Yanzheng Gao
Environmental persistence of free DNA is influenced by its complexation with other chemical species and its aggregation mechanisms. However, it is not well-known how naturally-abundant metal ions, e.g., Al(III) and Fe(III), influence DNA aggregation. This study investigated aggregation behaviors of model DNA from salmon testes as influenced by metal cations, and elucidated the predominant mechanism responsible for DNA aggregation. Compared to monovalent (K(+) and Na(+)) and divalent (Ca(2+) and Mg(2+)) cations, Al(III) and Fe(III) species in aqueous solution caused rapid DNA aggregations...
June 18, 2017: Water Research
https://www.readbyqxmd.com/read/28645025/decreased-functional-connectivity-and-disrupted-neural-network-in-the-prefrontal-cortex-of-affective-disorders-a-resting-state-fnirs-study
#3
Huilin Zhu, Jie Xu, Jiangxue Li, Hongjun Peng, Tingting Cai, Xinge Li, Shijing Wu, Wei Cao, Sailing He
BACKGROUND: Affective disorders (AD) have been conceptualized as neural network-level diseases. In this study, we utilized functional near infrared spectroscopy (fNIRS) to investigate the spontaneous hemodynamic activities in the prefrontal cortex (PFC) of the AD patients with or without medications. METHODS: 42 optical channels were applied to cover the superior frontal gyrus (SFG), middle frontal gyrus (MFG), and inferior frontal gyrus (IFG), which constitute one of the most important affective networks of the brain...
June 17, 2017: Journal of Affective Disorders
https://www.readbyqxmd.com/read/28645015/mid-infrared-and-near-infrared-spectroscopy-for-rapid-detection-of-gardeniae-fructus-by-a-liquid-liquid-extraction-process
#4
Lingyan Tao, Zhonglin Lin, Jiashan Chen, Yongjiang Wu, Xuesong Liu
Gardeniae Fructus is widely used in the pharmaceutical industry, and many studies have confirmed its medical and economic value. In this study, samples collected from different liquid-liquid extraction batches of Gardeniae Fructus were detected by mid-infrared (MIR) and near-infrared (NIR) spectroscopy. Seven analytes, neochlorogenic acid (5-CQA), cryptochlorogenic acid (4-CQA), chlorogenic acid (3-CQA), geniposidic acid (GEA), deacetyl-asperulosidic acid methyl ester (DAAME), genipin-gentiobioside (GGB), and gardenoside (GA), were chosen as quality property indexes of Gardeniae Fructus...
June 16, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/28644914/the-role-of-expectation-in-multisensory-body-representation-neural-evidence
#5
Francesca Ferri, Ettore Ambrosini, Paola Pinti, Arcangelo Merla, Marcello Costantini
Sensory events contribute to body ownership, the feeling that the body belongs to me. However, the encoding of sensory events is not only reactive, but also proactive in that our brain generates prediction about forthcoming stimuli. In previous studies we have shown that prediction of sensory events is a sufficient condition to induce the sense of body ownership. In this study we investigate the underlying neural mechanisms. Participants were seated with their right arm resting upon a table just below another smaller table...
June 23, 2017: European Journal of Neuroscience
https://www.readbyqxmd.com/read/28642548/hemodynamics-of-speech-production-an-fnirs-investigation-of-children-who-stutter
#6
B Walsh, F Tian, J A Tourville, M A Yücel, T Kuczek, A J Bostian
Stuttering affects nearly 1% of the population worldwide and often has life-altering negative consequences, including poorer mental health and emotional well-being, and reduced educational and employment achievements. Over two decades of neuroimaging research reveals clear anatomical and physiological differences in the speech neural networks of adults who stutter. However, there have been few neurophysiological investigations of speech production in children who stutter. Using functional near-infrared spectroscopy (fNIRS), we examined hemodynamic responses over neural regions integral to fluent speech production including inferior frontal gyrus, premotor cortex, and superior temporal gyrus during a picture description task...
June 22, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28642340/cardiovascular-and-cerebral-hemodynamics-during-exercise-and-recovery-in-obese-individuals-as-a-function-of-their-fitness-status
#7
Mathieu Gayda, Gabriel Lapierre, Olivier Dupuy, Sarah Fraser, Louis Bherer, Martin Juneau, Vincent Gremeaux, Anil Nigam
The aim of this study was to compare cardiovascular hemodynamics and cerebral oxygenation/perfusion (COP) during and after maximal incremental exercise in obese individuals according to their aerobic fitness versus age-matched healthy controls (AMHC). Fifty-four middle-aged obese (OB) and 16 AMHC were recruited. Maximal cardiopulmonary function (gas exchange analysis), cardiac hemodynamics (impedance cardiography), and left frontal COP (near-infrared spectroscopy: NIRS) were measured continuously during a maximal incremental ergocycle test...
June 2017: Physiological Reports
https://www.readbyqxmd.com/read/28641441/the-closo-si12c12-molecule-from-cluster-to-crystal-effects-of-hydrogenation-and-oligomerization-on-excited-states
#8
Xiaofeng F Duan, Larry W Burggraf
Excited state properties of chain and cyclic oligomers of closo-Si12C12 moieties are calculated using time-dependent density functional theory methods. Ultraviolet, visible, and near-infrared photo-absorption properties are described for oligomers that form by linking closo-Si12C12 monomer moieties through Si-Si bonds. Natural transition orbitals for electron and hole states of stationary-state excitons in oligomers were compared to understand how exciton states are influenced by oligomer structure. Depending on the structure, some prominent excited states have large electron-hole charge separation while others do not; some exhibit exciton delocalization while others do not...
June 21, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28639837/measuring-cerebrovascular-autoregulation-in-preterm-infants-using-near-infrared-spectroscopy-an-overview-of-the-literature
#9
Elisabeth M W Kooi, Elise A Verhagen, Jan Willem J Elting, Marek Czosnyka, Topun Austin, Flora Y Wong, Marcel J H Aries
The preterm born infant's ability to regulate its cerebral blood flow (CBF) is crucial in preventing secondary ischemic and hemorrhagic damage in the developing brain. The relationship between arterial blood pressure (ABP) and CBF estimates, such as regional cerebral oxygenation as measured by near-infrared spectroscopy (NIRS), is an attractive option for continuous non-invasive assessment of cerebrovascular autoregulation. Areas covered: The authors performed a literature search to provide an overview of the current literature on various current clinical practices and methods to measure cerebrovascular autoregulation in the preterm infant by NIRS...
June 22, 2017: Expert Review of Neurotherapeutics
https://www.readbyqxmd.com/read/28639666/conformational-landscape-of-the-sf6-dimer-as-revealed-by-high-resolution-infrared-spectroscopy-and-complexation-with-rare-gas-atoms
#10
Pierre Asselin, Alexey Potapov, Andrew C Turner, Vincent Boudon, Laurent Bruel, Marc-André Gaveau, Michel Mons
Taking advantage of a versatile set-up, combining pulsed pin hole or slit nozzle supersonic expansion with an external cavity quantum cascade laser, the rovibrational absorption spectrum of the SF6 dimer in the ν3 mode region has been revisited at high resolution under various experimental conditions in SF6:He mixtures. Two new rotationally resolved spectral bands have been identified in the range of the parallel band of the dimer spectrum in addition to that previously reported. Among these three spectral features, two of them are assigned to conformations of the dimer (noted #1 and #2), clearly distinguished from their different S-S interatomic distances, i...
June 22, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28636067/dynamic-time-warping-based-averaging-framework-for-functional-near-infrared-spectroscopy-brain-imaging-studies
#11
Li Zhu, Laleh Najafizadeh
No abstract text is available yet for this article.
June 1, 2017: Journal of Biomedical Optics
https://www.readbyqxmd.com/read/28635348/hope-coping-skills-and-the-prefrontal-cortex-in-alcohol-use-disorder-recovery
#12
Spencer D Bradshaw, Sterling T Shumway, Cynthia M Dsauza, Neli Morris, Nicholas D Hayes
BACKGROUND: Alcohol use disorders adversely affect individual and societal health. These disorders are a chronic brain disease, and protective factors against relapse should be studied. Prefrontal cortex (PFC) dysfunction is evident in alcohol use disorders, and research that explores recovery of the PFC in alcohol use disorders is needed, specifically in regard to how psychological and behavioral factors can augment medicalized treatments and protect against relapse. For example, hope or a belief that recovery is possible is an important cognitive construct-thought to precede behavioral action-that has been associated with relapse...
March 1, 2017: American Journal of Drug and Alcohol Abuse
https://www.readbyqxmd.com/read/28634025/impaired-cerebral-autoregulation-in-preoperative-newborn-infants-with-congenital-heart-disease
#13
Jodie K Votava-Smith, Christopher J Statile, Michael D Taylor, Eileen C King, Jesse M Pratt, David P Nelson, Erik C Michelfelder
OBJECTIVES: To characterize cerebral autoregulation (CA) in preoperative newborn infants with congenital heart disease (CHD). METHODS: This was a prospective, pilot study of term newborns with CHD who required intensive care. Continuous mean arterial blood pressure (MAP), cerebral tissue oxygen saturation (SCTO2) via near-infrared spectroscopy, and arterial oxygen saturation (SaO2) were collected. Significant low-frequency coherence between MAP and SCTO2 was used to define impaired CA in 20-minute epochs...
May 23, 2017: Journal of Thoracic and Cardiovascular Surgery
https://www.readbyqxmd.com/read/28631348/updating-of-working-memory-in-ecstasy-polydrug-users-findings-from-fnirs
#14
Catharine Montgomery, John E Fisk, Carl A Roberts
AIMS/OBJECTIVES: Cognitive deficits are now well documented in ecstasy (MDMA) users with type and relative demand of task emerging as important factors. The updating component of executive processes appears to be particularly affected. The study reported here used functional near infrared spectroscopy imaging to investigate changes in cortical haemodynamics during memory updating. METHOD: Twenty ecstasy users and 20 non-users completed verbal and spatial memory updating tasks and brain blood oxygenation and deoxygenation change was measured using functional near infrared spectroscopy...
June 19, 2017: Human Psychopharmacology
https://www.readbyqxmd.com/read/28630878/prediction-of-brain-tissue-temperature-using-near-infrared-spectroscopy
#15
Lisa Holper, Subhabrata Mitra, Gemma Bale, Nicola Robertson, Ilias Tachtsidis
Broadband near-infrared spectroscopy (NIRS) can provide an endogenous indicator of tissue temperature based on the temperature dependence of the water absorption spectrum. We describe a first evaluation of the calibration and prediction of brain tissue temperature obtained during hypothermia in newborn piglets (animal dataset) and rewarming in newborn infants (human dataset) based on measured body (rectal) temperature. The calibration using partial least squares regression proved to be a reliable method to predict brain tissue temperature with respect to core body temperature in the wavelength interval of 720 to 880 nm with a strong mean predictive power of [Formula: see text] (animal dataset) and [Formula: see text] (human dataset)...
April 2017: Neurophotonics
https://www.readbyqxmd.com/read/28628576/the-insight-from-foresight-near-infrared-spectroscopy-in-cyanotic-congenital-heart-disease
#16
Adam C Adler, Stephen A Stayer
No abstract text is available yet for this article.
July 2017: Anesthesia and Analgesia
https://www.readbyqxmd.com/read/28628557/excessive-hemodynamic-activity-in-the-superior-frontal-cortex-during-the-flanker-task-in-children-with-attention-deficit-hyperactivity-disorder
#17
Kota Suzuki, Yasuko Okumura, Yosuke Kita, Yuhei Oi, Yushiro Yamashita, Takaaki Goto, Masumi Inagaki
Near-infrared spectroscopy studies in children with attention deficit hyperactivity disorder (ADHD) have shown excessive prefrontal activity responsible for coping with interference. However, it is possible that the previous results were influenced by verbal, reading, and memory developments. The flanker task is an interference task that does not require a verbal response, reading, or memorization. We examined activity in the superior frontal cortex (SFC) during the flanker task in 12 children with ADHD and 14 children with typical development using near-infrared spectroscopy...
June 16, 2017: Neuroreport
https://www.readbyqxmd.com/read/28628483/sige-layer-thickness-effect-on-the-structural-and-optical-properties-of-well-organized-sige-sio2-multilayers
#18
Eliana Vieira, Johann Toudert, Anabela Gomes Rolo, Andrea Parisini, Joaquim Leitão, Maria Rosario Correia, Nuno Franco, Eduardo Alves, Adil Chahboun, Javier Martin-Sanchez, Rosalia Serna, Maria de Jesus de Matos Gomes
In this work, we report on the production of regular (SiGe/SiO2)20 multilayer structures by conventional RF-magnetron sputtering, at 350 ºC. Transmission electron microscopy, scanning transmission electron microscopy, raman spectroscopy, and X-ray reflectometry measurements revealed that annealing at a temperature of 1000 ºC lead to the formation of SiGe nanocrystals between SiO2 thin layers with good multilayer stability. Reducing the nominal SiGe layer thickness (tSiGe) from 3.5 to 2 nm results in a transition from continuous SiGe crystalline layer (tSiGe ~ 3...
June 19, 2017: Nanotechnology
https://www.readbyqxmd.com/read/28627542/gas-phase-vibrational-spectroscopy-of-triphenylamine-the-effect-of-charge-on-structure-and-spectra
#19
Musleh Uddin Munshi, Giel Berden, Jonathan Martens, Jos Oomens
The effect of ionization by oxidation and protonation on the structure and IR spectrum of isolated, gas-phase triphenylamine (TPA) has been investigated by infrared multiple photon dissociation (IRMPD) spectroscopy in the fingerprint range from 600 cm(-1) to 1800 cm(-1) using an infrared free electron laser. IR spectra calculated using density functional theory (DFT) convincingly reproduce the experimental data. Spectral and structural differences are identified among neutral TPA, TPA˙(+) and protonated TPA and qualitatively related to effects of resonance delocalization...
June 19, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28627364/modulating-perceptual-complexity-and-load-reveals-degradation-of-the-visual-working-memory-network-in-ageing
#20
Sobanawartiny Wijeakumar, Vincent A Magnotta, John P Spencer
Previous neuroimaging studies have reported a posterior to anterior shift of activation in ageing (PASA). Here, we explore the nature of this shift by modulating load (1,2 or 3 items) and perceptual complexity in two variants of a visual working memory task (VWM): a 'simple' color and a 'complex' shape change detection task. Functional near-infrared spectroscopy (fNIRS) was used to record changes in activation in younger (N=24) and older adults (N=24). Older adults exhibited PASA by showing lesser activation in the posterior cortex and greater activation in the anterior cortex when compared to younger adults...
June 14, 2017: NeuroImage
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