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HIgh Frequency Oscillation

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https://www.readbyqxmd.com/read/28718301/web-addiction-in-the-brain-cortical-oscillations-autonomic-activity-and-behavioral-measures
#1
Michela Balconi, Salvatore Campanella, Roberta Finocchiaro
Background and aims Internet addiction (IA) was recently defined as a disorder tagging both the impulse control and the reward systems. Specifically, inhibitory deficits and reward bias were considered highly relevant in IA. This research aims to examine the electrophysiological correlates and autonomic activity [skin conductance response (SCR) and heart rate] in two groups of young subjects (N = 25), with high or low IA profile [tested by the Internet Addiction Test (IAT)], with specific reference to gambling behavior...
July 18, 2017: Journal of Behavioral Addictions
https://www.readbyqxmd.com/read/28714094/selective-high-frequency-mechanical-actuation-driven-by-the-vo2-electronic-instability
#2
Nicola Manca, Luca Pellegrino, Teruo Kanki, Warner J Venstra, Giordano Mattoni, Yoshiyuki Higuchi, Hidekazu Tanaka, Andrea D Caviglia, Daniele Marré
Relaxation oscillators consist of periodic variations of a physical quantity triggered by a static excitation. They are a typical consequence of nonlinear dynamics and can be observed in a variety of systems. VO2 is a correlated oxide with a solid-state phase transition above room temperature, where both electrical resistance and lattice parameters undergo a drastic change in a narrow temperature range. This strong nonlinear response allows to realize spontaneous electrical oscillations in the megahertz range under a DC voltage bias...
July 17, 2017: Advanced Materials
https://www.readbyqxmd.com/read/28709992/time-dependent-evolution-of-seizures-in-a-model-of-mesial-temporal-lobe-epilepsy
#3
Charles Behr, Maxime Lévesque, Thomas Stroh, Massimo Avoli
Low-voltage fast (LVF) and hypersynchronous (HYP) - onset seizures occur in the EEG obtained with depth electrodes from mesial temporal lobe epilepsy (MTLE) patients and animal models. In epileptic rats analyzed up to approximately two weeks after pilocarpine-induced status epilepticus (SE), these patterns are associated with specific high-frequency oscillation (HFO) content: ripples (80-200Hz) or fast-ripples (250-500Hz) predominate in LVF or HYP seizures, respectively. To establish whether these features change over the course of the disease, we recorded the EEG from the hippocampal CA3 subfield, subiculum, entorhinal cortex and dentate gyrus in two groups of pilocarpine-treated rats: the "early stage group" (n=8) was analyzed from day 3 to 20 post-SE while the "late stage group" (n=7) was studied from day 27 to 53 post-SE...
July 12, 2017: Neurobiology of Disease
https://www.readbyqxmd.com/read/28708140/wideband-tunable-opto-electronic-oscillator-based-on-frequency-translation
#4
Zeev Tamir, Asher Meltzer, Moshe Horowitz
We demonstrate a new method to obtain a widely tunable low phase-noise opto-electronic oscillator (OEO), based on translating the OEO signal into a lower intermediate frequency (IF) signal. The OEO signal is downconverted to IF by using a local oscillator (LO) signal, filtered by a high-Q filter; its frequency is then upconverted back into the high OEO frequency. The combination of a narrowband filter at a fixed central frequency with a tunable LO forms a tunable high-Q bandpass filter (BPF) that can be used to change the OEO frequency over a broad frequency region...
July 15, 2017: Optics Letters
https://www.readbyqxmd.com/read/28702575/multi-walled-boron-nitride-nanotubes-as-self-excited-launchers
#5
Yifan Li, Yi Zhou, Yan Wu, Chengchi Huang, Long Wang, Xuyan Zhou, Zhenyang Zhao, Hui Li
A self-excited launcher consisting of multi-walled boron nitride nanotubes (BNNTs) has been investigated using molecular dynamics simulation. The results show that, after a period of high frequency oscillation, the innermost BNNT can be spontaneously ejected along its central axis at a relatively fast speed. The launching is caused by the energy transfer between the nanotubes and without absorbing energy from the external environment. Most self-excited launchers could launch their innermost nanotube, although an inappropriate structure of the nanotubes contributes to a blocked or failed launch...
July 12, 2017: Nanoscale
https://www.readbyqxmd.com/read/28702346/automatic-detection-and-visualisation-of-meg-ripple-oscillations-in-epilepsy
#6
Nicole van Klink, Frank van Rosmalen, Jukka Nenonen, Sergey Burnos, Liisa Helle, Samu Taulu, Paul Lawrence Furlong, Maeike Zijlmans, Arjan Hillebrand
High frequency oscillations (HFOs, 80-500 Hz) in invasive EEG are a biomarker for the epileptic focus. Ripples (80-250 Hz) have also been identified in non-invasive MEG, yet detection is impeded by noise, their low occurrence rates, and the workload of visual analysis. We propose a method that identifies ripples in MEG through noise reduction, beamforming and automatic detection with minimal user effort. We analysed 15 min of presurgical resting-state interictal MEG data of 25 patients with epilepsy. The MEG signal-to-noise was improved by using a cross-validation signal space separation method, and by calculating ~ 2400 beamformer-based virtual sensors in the grey matter...
2017: NeuroImage: Clinical
https://www.readbyqxmd.com/read/28700096/peak-alpha-frequency-is-a-neural-marker-of-cognitive-function-across-the-autism-spectrum
#7
Abigail Dickinson, Charlotte DiStefano, Damla Senturk, Shafali Spurling Jeste
Cognitive function varies substantially and serves as a key predictor of outcome and response to intervention in autism spectrum disorder (ASD), yet we know little about the neurobiological mechanisms that underlie cognitive function in children with ASD. The dynamics of neuronal oscillations in the alpha range (6-12 Hz) are associated with cognition in typical development. Peak alpha frequency is also highly sensitive to developmental changes in neural networks which underlie cognitive function, and therefore it holds promise as a developmentally-sensitive neural marker of cognitive function in ASD...
July 12, 2017: European Journal of Neuroscience
https://www.readbyqxmd.com/read/28699704/aberrant-blood-oxygen-level-dependent-signal-oscillations-across-frequency-bands-characterize-the-alcoholic-brain
#8
Jui-Yang Hong, Eva M Müller-Oehring, Adolf Pfefferbaum, Edith V Sullivan, Dongjin Kwon, Tilman Schulte
Chronic alcoholism is associated with widespread regional differences from controls in brain activity and connectivity dynamics measured by blood-oxygen-level-dependent (BOLD) signals. Identification of alcoholism-related neurofunctional power dynamics using functional magnetic resonance imaging (fMRI) that relate to cognition and behavior may serve as biomarkers of alcoholism. Previously, resting-state fMRI studies examined BOLD signals at a single low-frequency (LF) bandwidth. BOLD signals, however, oscillate systematically at different frequencies and are organized in a resting brain where LF oscillation facilitates long-distance communication between regions across cortical regions, whereas high-frequency (HF) oscillation occurs in closely localized, subcortical areas...
July 12, 2017: Addiction Biology
https://www.readbyqxmd.com/read/28696761/parametric-oscillation-frequency-mixing-and-injection-locking-of-strongly-coupled-nanomechanical-resonator-modes
#9
Maximilian J Seitner, Mehdi Abdi, Alessandro Ridolfo, Michael J Hartmann, Eva M Weig
We study locking phenomena of two strongly coupled, high quality factor nanomechanical resonator modes to a common parametric drive at a single drive frequency in different parametric driving regimes. By controlled dielectric gradient forces we tune the resonance frequencies of the flexural in-plane and out-of-plane oscillation of the high stress silicon nitride string through their mutual avoided crossing. For the case of the strong common parametric drive signal-idler generation via nondegenerate parametric two-mode oscillation is observed...
June 23, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28696734/coherent-transfer-between-low-angular-momentum-and-circular-rydberg-states
#10
A Signoles, E K Dietsche, A Facon, D Grosso, S Haroche, J M Raimond, M Brune, S Gleyzes
We realize a coherent transfer between a laser-accessible low-angular-momentum Rydberg state and the circular Rydberg level with maximal angular momentum. It is induced by a radio frequency field with a high-purity σ^{+} polarization resonant on Stark transitions inside the hydrogenic Rydberg manifold. We observe over a few microseconds more than 20 coherent Rabi oscillations between the initial Rydberg state and the circular level. We characterize these many-Rydberg-level oscillations and find them in perfect agreement with a simple model...
June 23, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28694489/high-frequency-components-of-hemodynamic-shear-stress-profiles-are-a-major-determinant-of-shear-mediated-platelet-activation-in-therapeutic-blood-recirculating-devices
#11
Filippo Consolo, Jawaad Sheriff, Silvia Gorla, Nicolò Magri, Danny Bluestein, Federico Pappalardo, Marvin J Slepian, Gianfranco B Fiore, Alberto Redaelli
We systematically analyzed the relative contributions of frequency component elements of hemodynamic shear stress waveforms encountered in cardiovascular blood recirculating devices as to overall platelet activation over time. We demonstrated that high frequency oscillations are the major determinants for priming, triggering and yielding activated "prothrombotic behavior" for stimulated platelets, even if the imparted shear stress has low magnitude and brief exposure time. Conversely, the low frequency components of the stress signal, with limited oscillations over time, did not induce significant activation, despite being of high magnitude and/or exposure time...
July 10, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28693425/cyclic-pao2-oscillations-assessed-in-the-renal-microcirculation-correlation-with-tidal-volume-in-a-porcine-model-of-lung-lavage
#12
Rainer Thomas, Christian Möllmann, Alexander Ziebart, Tanghua Liu, Matthias David, Erik K Hartmann
BACKGROUND: Oscillations of the arterial partial pressure of oxygen induced by varying shunt fractions occur during cyclic alveolar recruitment within the injured lung. Recently, these were proposed as a pathomechanism that may be relevant for remote organ injury following acute respiratory distress syndrome. This study examines the transmission of oxygen oscillations to the renal tissue and their tidal volume dependency. METHODS: Lung injury was induced by repetitive bronchoalveolar lavage in eight anaesthetized pigs...
July 11, 2017: BMC Anesthesiology
https://www.readbyqxmd.com/read/28691853/assessment-of-cardiac-autonomic-tone-following-long-sudarshan-kriya-yoga-in-art-of-living-practitioners
#13
Lakshmi Bhaskar, Chhaya Kharya, K K Deepak, Vinod Kochupillai
OBJECTIVE: The breathing processes are known to modulate cardiac autonomic tone and improve psychological status. We investigated cardiac autonomic tone following long Sudarshan Kriya Yoga (SKY) using heart rate variability (HRV) and skin conductance level (SCL). METHODS: Thirty healthy volunteers (age 28.3 ± 8.4 years; 23 M: 7 F) participated in the study. Electrocardiogram (ECG) and SCL were recorded for 5 min each, before and after long SKY. Long SKY is a combination of pranayama and cyclic rhythmic breathing and is performed by following the guided audio instructions...
July 10, 2017: Journal of Alternative and Complementary Medicine: Research on Paradigm, Practice, and Policy
https://www.readbyqxmd.com/read/28690102/high-frequency-oscillations-after-median-nerve-stimulations-in-healthy-children-and-adolescents
#14
Sergio Zanini, Ivana Del Piero, Lucia Martucci, Domenico Restuccia
The aim of the present research was to address somatosensory high frequency oscillations (400-800Hz) in healthy children and adolescents in comparison with healthy adults. We recorded somatosensory evoked potentials following median nerve stimulation in nineteen resting healthy children/adolescents and in nineteen resting healthy adults with eyes closed. We administered six consecutive stimulation blocks (500 sweeps each). The presynaptic component of high frequency oscillations amplitudes was smaller in healthy children/adolescents than in healthy adults (no difference between groups was found as far as the postsynaptic component was concerned)...
July 6, 2017: International Journal of Developmental Neuroscience
https://www.readbyqxmd.com/read/28684752/on-chip-coherent-detection-with-quantum-limited-sensitivity
#15
Vadim Kovalyuk, Simone Ferrari, Oliver Kahl, Alexander Semenov, Michael Shcherbatenko, Yury Lobanov, Roman Ozhegov, Alexander Korneev, Nataliya Kaurova, Boris Voronov, Wolfram Pernice, Gregory Gol'tsman
While single photon detectors provide superior intensity sensitivity, spectral resolution is usually lost after the detection event. Yet for applications in low signal infrared spectroscopy recovering information about the photon's frequency contributions is essential. Here we use highly efficient waveguide integrated superconducting single-photon detectors for on-chip coherent detection. In a single nanophotonic device, we demonstrate both single-photon counting with up to 86% on-chip detection efficiency, as well as heterodyne coherent detection with spectral resolution f/∆f exceeding 10(11)...
July 6, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28681378/update-on-the-mechanisms-and-roles-of-high-frequency-oscillations-in-seizures-and-epileptic-disorders
#16
REVIEW
Premysl Jiruska, Catalina Alvarado-Rojas, Catherine A Schevon, Richard Staba, William Stacey, Fabrice Wendling, Massimo Avoli
High-frequency oscillations (HFOs) are a type of brain activity that is recorded from brain regions capable of generating seizures. Because of the close association of HFOs with epileptogenic tissue and ictogenesis, understanding their cellular and network mechanisms could provide valuable information about the organization of epileptogenic networks and how seizures emerge from the abnormal activity of these networks. In this review, we summarize the most recent advances in the field of HFOs and provide a critical evaluation of new observations within the context of already established knowledge...
July 6, 2017: Epilepsia
https://www.readbyqxmd.com/read/28679262/laser-driven-resonance-of-dye-doped-oil-coated-microbubbles-experimental-study
#17
Guillaume Lajoinie, Jeong-Yu Lee, Joshua Owen, Pieter Kruizinga, Nico de Jong, Gijs van Soest, Eleanor Stride, Michel Versluis
Photoacoustic (PA) imaging offers several attractive features as a biomedical imaging modality, including excellent spatial resolution and functional information such as tissue oxygenation. A key limitation, however, is the contrast to noise ratio that can be obtained from tissue depths greater than 1-2 mm. Microbubbles coated with an optically absorbing shell have been proposed as a possible contrast agent for PA imaging, offering greater signal amplification and improved biocompatibility compared to metallic nanoparticles...
June 2017: Journal of the Acoustical Society of America
https://www.readbyqxmd.com/read/28679124/pharynx-mitochondrial-ca2-dynamics-in-live-c-elegans-worms-during-aging
#18
Pilar Alvarez-Illera, Paloma García-Casas, Jessica Arias-Del-Val, Rosalba I Fonteriz, Javier Alvarez, Mayte Montero
Progressive decline in mitochondrial function is generally considered one of the hallmarks of aging. We have expressed a Ca2+ sensor in the mitochondrial matrix of C. elegans pharynx cells and we have measured for the first time mitochondrial [Ca2+] ([Ca2+]M) dynamics in the pharynx of live C. elegans worms during aging. Our results show that worms stimulated with serotonin display a pharynx [Ca2+]M oscillatory kinetics that includes both high frequency oscillations (up to about 1Hz) and very prolonged "square-wave" [Ca2+]M increases, indicative of energy depletion of the pharynx cells...
June 22, 2017: Oncotarget
https://www.readbyqxmd.com/read/28676240/local-nmda-receptor-hypofunction-evokes-generalized-effects-on-gamma-and-high-frequency-oscillations-and-behavior
#19
Jaime Lee, Matthew R Hudson, Terence J O'Brien, Jess Nithianantharajah, Nigel C Jones
The NMDA receptor (NMDAr) hypofunction theory of schizophrenia suggests that aberrant signaling through NMDAr underlies the pathophysiology of this disease. This is commonly modeled in rodents via treatment with NMDAr antagonists, which causes a range of behavioral effects that represent endophenotypes related to schizophrenia. These drugs also disrupt high-frequency neural oscillations within the brain, also potentially relevant to disease. We studied the effect of localized NMDAr hypofunction on the generation of neural oscillations occurring both locally and in distant brain regions, and on behaviors routinely used as endophenotypes to model psychosis in rodents...
July 1, 2017: Neuroscience
https://www.readbyqxmd.com/read/28674460/high-speed-logic-integrated-circuits-with-solution-processed-self-assembled-carbon-nanotubes
#20
Shu-Jen Han, Jianshi Tang, Bharat Kumar, Abram Falk, Damon Farmer, George Tulevski, Keith Jenkins, Ali Afzali, Satoshi Oida, John Ott, James Hannon, Wilfried Haensch
As conventional monolithic silicon technology struggles to meet the requirements for the 7-nm technology node, there has been tremendous progress in demonstrating the scalability of carbon nanotube field-effect transistors down to the size that satisfies the 3-nm node and beyond. However, to date, circuits built with carbon nanotubes have overlooked key aspects of a practical logic technology and have stalled at simple functionality demonstrations. Here, we report high-performance complementary carbon nanotube ring oscillators using fully manufacturable processes, with a stage switching frequency of 2...
July 3, 2017: Nature Nanotechnology
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