keyword
MENU ▼
Read by QxMD icon Read
search

HIgh Frequency Oscillation

keyword
https://www.readbyqxmd.com/read/28794978/localization-of-beta-and-high-frequency-oscillations-within-the-subthalamic-nucleus-region
#1
B C M van Wijk, A Pogosyan, M I Hariz, H Akram, T Foltynie, P Limousin, A Horn, S Ewert, P Brown, V Litvak
Parkinsonian bradykinesia and rigidity are typically associated with excessive beta band oscillations in the subthalamic nucleus. Recently another spectral peak has been identified that might be implicated in the pathophysiology of the disease: high-frequency oscillations (HFO) within the 150-400 Hz range. Beta-HFO phase-amplitude coupling (PAC) has been found to correlate with severity of motor impairment. However, the neuronal origin of HFO and its usefulness as a potential target for deep brain stimulation remain to be established...
2017: NeuroImage: Clinical
https://www.readbyqxmd.com/read/28783620/reducing-sensor-noise-in-meg-and-eeg-recordings-using-oversampled-temporal-projection
#2
Eric Larson, Samu Taulu
Here we review the theory of suppression of spatially uncorrelated, sensor-specific noise in electro- and magento-encephalography (EEG and MEG) arrays, and introduce a novel method for suppression. Our method requires only that the signals of interest are spatially oversampled by the sensor array, which is a reasonable assumption for many EEG and MEG systems. Our method is based on a leave-one-out procedure using overlapping temporal windows in a mathematical framework to project spatially uncorrelated noise in the temporal domain...
July 31, 2017: IEEE Transactions on Bio-medical Engineering
https://www.readbyqxmd.com/read/28773944/wire-arc-additive-manufacturing-of-az31-magnesium-alloy-grain-refinement-by-adjusting-pulse-frequency
#3
Jing Guo, Yong Zhou, Changmeng Liu, Qianru Wu, Xianping Chen, Jiping Lu
Wire arc additive manufacturing (WAAM) offers a potential approach to fabricate large-scale magnesium alloy components with low cost and high efficiency, although this topic is yet to be reported in literature. In this study, WAAM is preliminarily applied to fabricate AZ31 magnesium. Fully dense AZ31 magnesium alloy components are successfully obtained. Meanwhile, to refine grains and obtain good mechanical properties, the effects of pulse frequency (1, 2, 5, 10, 100, and 500 Hz) on the macrostructure, microstructure and tensile properties are investigated...
October 9, 2016: Materials
https://www.readbyqxmd.com/read/28770093/the-clinical-practice-guideline-for-the-management-of-ards-in-japan
#4
Satoru Hashimoto, Masamitsu Sanui, Moritoki Egi, Shinichiro Ohshimo, Junji Shiotsuka, Ryutaro Seo, Ryoma Tanaka, Yu Tanaka, Yasuhiro Norisue, Yoshiro Hayashi, Eishu Nango
BACKGROUND: The Japanese Society of Respiratory Care Medicine and the Japanese Society of Intensive Care Medicine provide here a clinical practice guideline for the management of adult patients with ARDS in the ICU. METHOD: The guideline was developed applying the GRADE system for performing robust systematic reviews with plausible recommendations. The guideline consists of 13 clinical questions mainly regarding ventilator settings and drug therapies (the last question includes 11 medications that are not approved for clinical use in Japan)...
2017: Journal of Intensive Care
https://www.readbyqxmd.com/read/28764509/note-temperature-effects-in-the-modified-howland-current-source-for-electrical-bioimpedance-spectroscopy
#5
S Fernandez Santos, P Bertemes-Filho
The aim of this study is to show how the modified Howland current source (MHCS) is affected by temperature changes. The source has been tested in a temperature range from 20 to 70 °C and frequency range from 100 Hz to 1 MHz. Parameters like output current, output impedance, total harmonic distortion, and oscillation have been measured. The measurements were made inside a temperature controlled environment. It was showed that the MHCS is stable at temperatures below 70 °C. Operational amplifiers with a low temperature drift and matching resistor should be carefully considered in order to prevent oscillations at high temperatures...
July 2017: Review of Scientific Instruments
https://www.readbyqxmd.com/read/28762890/the-latency-of-the-light-response-is-modulated-by-the-phosphorylation-state-of-drosophila-trp-at-a-specific-site
#6
Ben Katz, Olaf Voolstra, Hanan Tzadok, Bushra Yasin, Elisheva Rhodes-Modrov, Jonas-Peter Bartels, Lisa Strauch, Armin Huber, Baruch Minke
Drosophila photoreceptors respond to oscillating light of high frequency (∼100 Hz), while increasing the oscillating light intensity raises the maximally detected frequency. Recently, we reported that dephosphorylation of the light-activated TRP ion channel at S936 is a fast, graded, light-, and Ca(2+)-dependent process. We further found that this process affects the detection limit of high frequency oscillating light. Accordingly, transgenic Drosophila, which do not undergo phosphorylation at the S936-TRP site (trp(S936A)), revealed a short time-interval before following the high stimulus frequency (oscillation-lock response) in both dark- and light-adapted flies...
August 1, 2017: Channels
https://www.readbyqxmd.com/read/28762469/impairment-of-gabaergic-system-contributes-to-epileptogenesis-in-glutaric-acidemia-type-i
#7
Mayara Vendramin Pasquetti, Letícia Meier, Samanta Loureiro, Marcelo Ganzella, Bernardo Junges, Letícia Barbieri Caus, Alexandre Umpierrez Amaral, David M Koeller, Stephen Goodman, Michael Woontner, Diogo Onofre Gomes de Souza, Moacir Wajner, Maria Elisa Calcagnotto
OBJECTIVES: Glutaric acidemia type I (GA-I) is an inherited neurometabolic disorder caused by deficiency of glutaryl-CoA dehydrogenase (GCDH) and characterized by increased levels of glutaric, 3-OH-glutaric, and glutaconic acids in the brain parenchyma. The increment of these organic acids inhibits glutamate decarboxylase (GAD) and consequently lowers the γ-aminobutyric acid (GABA) synthesis. Untreated patients exhibit severe neurologic deficits during development, including epilepsy, especially following an acute encephalopathy outbreak...
August 1, 2017: Epilepsia
https://www.readbyqxmd.com/read/28760982/low-frequency-hippocampal-cortical-activity-drives-brain-wide-resting-state-functional-mri-connectivity
#8
Russell W Chan, Alex T L Leong, Leon C Ho, Patrick P Gao, Eddie C Wong, Celia M Dong, Xunda Wang, Jufang He, Ying-Shing Chan, Lee Wei Lim, Ed X Wu
The hippocampus, including the dorsal dentate gyrus (dDG), and cortex engage in bidirectional communication. We propose that low-frequency activity in hippocampal-cortical pathways contributes to brain-wide resting-state connectivity to integrate sensory information. Using optogenetic stimulation and brain-wide fMRI and resting-state fMRI (rsfMRI), we determined the large-scale effects of spatiotemporal-specific downstream propagation of hippocampal activity. Low-frequency (1 Hz), but not high-frequency (40 Hz), stimulation of dDG excitatory neurons evoked robust cortical and subcortical brain-wide fMRI responses...
August 15, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28757237/ultrasound-induced-strain-cytoskeleton-rearrangement-an-experimental-and-simulation-study
#9
Mohamadmahdi Samandari, Karen Abrinia, Manijhe Mokhtari-Dizaji, Ali Tamayol
Cytoskeleton and specially actin filaments are responsible for mechanical modulation of cellular behavior. These structures could be fluidized in response to transient mechanical cues. Ultrasound devices have been widely used in medicine which their generated ultrasonic waves could disrupt/fluidize actin filaments in cytoskeleton and thus could affect cellular organization. Present research aims at revealing the mechanism of fluidization caused by ultrasound induced strains. First, a numerical simulation was performed to reveal the effect of oscillating ultrasonic pressure on induced deformation in the cell with respect to different cell geometries and exposure conditions...
June 20, 2017: Journal of Biomechanics
https://www.readbyqxmd.com/read/28757194/time-resolved-phase-amplitude-coupling-in-neural-oscillations
#10
Soheila Samiee, Sylvain Baillet
Cross-frequency coupling between neural oscillations is a phenomenon observed across spatial scales in a wide range of preparations, including human non-invasive electrophysiology. Although the functional role and mechanisms involved are not entirely understood, the concept of interdependent neural oscillations drives an active field of research to comprehend the ubiquitous polyrhythmic activity of the brain, beyond empirical observations. Phase-amplitude coupling, a particular form of cross-frequency coupling between bursts of high-frequency oscillations and the phase of lower frequency rhythms, has recently received considerable attention...
July 27, 2017: NeuroImage
https://www.readbyqxmd.com/read/28756240/frequency-specific-modulation-of-connectivity-in-the-ipsilateral-sensorimotor-cortex-by-different-forms-of-movement-initiation
#11
Bin A Wang, Shivakumar Viswanathan, Rouhollah O Abdollahi, Nils Rosjat, Svitlana Popovych, Silvia Daun, Christian Grefkes, Gereon R Fink
A consistent finding in motor EEG research is a bilateral attenuation of oscillatory activity over sensorimotor regions close to the onset of an upcoming unilateral hand movement. In contrast, little is known about how movement initiation affects oscillatory activity, especially in the hemisphere ipsilateral to the moving hand. We here investigated the neural mechanisms modulating oscillatory activity in the ipsilateral motor cortex prior to movement onset under the control of two different initiating networks, namely, Self-initiated and Visually-cued actions...
July 26, 2017: NeuroImage
https://www.readbyqxmd.com/read/28755648/cerebral-pet-glucose-hypometabolism-in-subjects-with-mild-cognitive-impairment-and-higher-eeg-high-alpha-low-alpha-frequency-power-ratio
#12
Davide Vito Moretti, Michela Pievani, Lorenzo Pini, Ugo Paolo Guerra, Barbara Paghera, Giovanni Battista Frisoni
In Alzheimer's disease (AD) research, both 2-deoxy-2-((18)F)fluoro-D-glucose (FDG) positron emission tomography (PET) and electroencephalography (EEG) are reliable investigational modalities. The aim of this study was to investigate the associations between EEG High-alpha/Low-alpha (H-alpha/L-alpha) power ratio and cortical glucose metabolism. A total of 23 subjects with mild cognitive impairment (MCI) underwent FDG-PET and EEG examinations. H-alpha/L-alpha power ratio was computed for each subject and 2 groups were obtained based on the increase of the power ratio...
June 24, 2017: Neurobiology of Aging
https://www.readbyqxmd.com/read/28755546/temporal-spatial-characteristics-of-phase-amplitude-coupling-in-electrocorticogram-for-human-temporal-lobe-epilepsy
#13
Ruihua Zhang, Ye Ren, Chunyan Liu, Na Xu, Xiaoli Li, Fengyu Cong, Tapani Ristaniemi, YuPing Wang
OBJECTIVE: Neural activity of the epileptic human brain contains low- and high-frequency oscillations in different frequency bands, some of which have been used as reliable biomarkers of the epileptogenic brain areas. However, the relationship between the low- and high-frequency oscillations in different cortical areas during the period from pre-seizure to post-seizure has not been completely clarified. METHODS: We recorded electrocorticogram data from the temporal lobe and hippocampus of seven patients with temporal lobe epilepsy...
June 28, 2017: Clinical Neurophysiology: Official Journal of the International Federation of Clinical Neurophysiology
https://www.readbyqxmd.com/read/28752895/development-of-resurgent-and-persistent-sodium-currents-in-mesencephalic-trigeminal-neurons
#14
Akifumi Enomoto, Soju Seki, Susumu Tanaka, Kohji Ishihama, Tadashi Yamanishi, Mikihiko Kogo, Suguru Hamada
Sodium channels play multiple roles in the formation of neural membrane properties in mesencephalic trigeminal (Mes V) neurons and in other neural systems. Mes V neurons exhibit conditional robust high-frequency spike discharges. As previously reported, resurgent and persistent sodium currents (INaR and INaP , respectively) may carry small currents at subthreshold voltages that contribute to generation of spike firing. These currents play an important role in maintaining and allowing high-frequency spike discharge during a burst...
July 28, 2017: Journal of Neuroscience Research
https://www.readbyqxmd.com/read/28751716/static-magnetic-field-stimulation-enhances-oligodendrocyte-differentiation-and-secretion-of-neurotrophic-factors
#15
Ankshita Prasad, Daniel B Loong Teh, Agata Blasiak, Chou Chai, Yang Wu, Payam M Gharibani, In Hong Yang, Thang T Phan, Kah Leong Lim, Hyunsoo Yang, Xiaogang Liu, Angelo H All
The cellular-level effects of low/high frequency oscillating magnetic field on excitable cells such as neurons are well established. In contrast, the effects of a homogeneous, static magnetic field (SMF) on Central Nervous System (CNS) glial cells are less investigated. Here, we have developed an in vitro SMF stimulation set-up to investigate the genomic effects of SMF exposure on oligodendrocyte differentiation and neurotrophic factors secretion. Human oligodendrocytes precursor cells (OPCs) were stimulated with moderate intensity SMF (0...
July 27, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28748408/a-simple-statistical-method-for-the-automatic-detection-of-ripples-in-human-intracranial-eeg
#16
K Charupanit, B A Lopour
High frequency oscillations (HFOs) are a promising biomarker of epileptic tissue, but detection of these electrographic events remains a challenge. Automatic detectors show encouraging results, but they typically require optimization of multiple parameters, which is a barrier to good performance and broad applicability. We therefore propose a new automatic HFO detection algorithm, focusing on simplicity and ease of implementation. It requires tuning of only an amplitude threshold, which can be determined by an iterative process or directly calculated from statistics of the rectified filtered data (i...
July 26, 2017: Brain Topography
https://www.readbyqxmd.com/read/28747881/frequency-unspecific-effects-of-%C3%AE-tacs-related-to-a-visuospatial-working-memory-task
#17
Maria-Lisa Kleinert, Caroline Szymanski, Viktor Müller
Working memory (WM) is crucial for intelligent cognitive functioning, and synchronization phenomena in the fronto-parietal network have been suggested as an underlying neural mechanism. In an attempt to provide causal evidence for this assumption, we applied transcranial alternating current stimulation (tACS) at theta frequency over fronto-parietal sites during a visuospatial match-to-sample (MtS) task. Depending on the stimulation protocol, i.e., in-phase, anti-phase or sham, we anticipated a differential impact of tACS on behavioral WM performance as well as on the EEG (electroencephalography) during resting state before and after stimulation...
2017: Frontiers in Human Neuroscience
https://www.readbyqxmd.com/read/28739525/state-dependent-alpha-peak-frequency-shifts-experimental-evidence-potential-mechanisms-and-functional-implications
#18
REVIEW
Andreas Mierau, Wolfgang Klimesch, Jérémie Lefebvre
Neural populations produce complex oscillatory patterns thought to implement brain function. The dominant rhythm in the healthy adult human brain is formed by alpha oscillations with a typical power peak most commonly found between 9 and 11Hz. This alpha peak frequency has been repeatedly discussed as a highly heritable and stable neurophysiological "trait" marker reflecting anatomical properties of the brain, and individuals' general cognitive capacity. However, growing evidence suggests that the alpha peak frequency is highly volatile at shorter time scales, dependent on the individuals' "state"...
July 22, 2017: Neuroscience
https://www.readbyqxmd.com/read/28738697/reduction-of-heart-rate-variability-in-hypertensive-elderly
#19
Paulo Evaristo de Andrade, Joice Anaize Tonon do Amaral, Laércio da Silva Paiva, Fernando Adami, Juliana Zangirolami Raimudo, Vitor Engrácia Valenti, Luiz Carlos de Abreu, Rodrigo Daminello Raimundo
INTRODUCTION: The elderly population grows globally every day, and along with it the incidence of high blood pressure also grows, following these data scientists seek tools to improve the health of this population, a widely used tool for assessing cardiovascular function is the heart rate variability(HRV), that is a mecanism that allows the investigation of oscillations in the intervals between consecutive heart beats (RR intervals). There are already studies on the autonomic nervous system in the elderly population, however, these studies investigated normotensive patients and there is little research in hypertensive patients...
July 24, 2017: Blood Pressure
https://www.readbyqxmd.com/read/28738310/postural-response-to-predictable-and-nonpredictable-visual-flow-in-children-and-adults
#20
Mark A Schmuckler
Children's (3-5years) and adults' postural reactions to different conditions of visual flow information varying in its frequency content was examined using a moving room apparatus. Both groups experienced four conditions of visual input: low-frequency (0.20Hz) visual oscillations, high-frequency (0.60Hz) oscillations, multifrequency nonpredictable visual input, and no imposed visual information. Analyses of the frequency content of anterior-posterior (AP) sway revealed that postural reactions to the single-frequency conditions replicated previous findings; children were responsive to low- and high-frequency oscillations, whereas adults were responsive to low-frequency information...
November 2017: Journal of Experimental Child Psychology
keyword
keyword
75237
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"