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https://www.readbyqxmd.com/read/28922535/power-and-coherence-of-cortical-high-frequency-oscillations-during-wakefulness-and-sleep
#1
Matías Cavelli, Daniel Rojas-Líbano, Natalia Schwarzkopf, Santiago Castro-Zaballa, Joaquín Gonzalez, Alejandra Mondino, Noelia Santana, Luciana Benedetto, Atilio Falconi, Pablo Torterolo
Recently, a novel type of fast cortical oscillatory activity that occurs between 110 and 160 Hz (high-frequency oscillations (HFO)) was described. HFO are modulated by the theta rhythm in hippocampus and neocortex during active wakefulness and REM sleep. Since theta-HFO coupling increases during REM, a role for HFO in memory consolidation has been proposed. However, global properties like the cortex-wide topographic distribution, and the cortico-cortical coherence remain unknown. In the present study, we recorded the electroencephalogram during sleep and wakefulness in the rat, and analyzed the spatial extent of the HFO band power and coherence...
September 18, 2017: European Journal of Neuroscience
https://www.readbyqxmd.com/read/28860077/the-cs-algorithm-a-novel-method-for-high-frequency-oscillation-detection-in-eeg
#2
Jan Cimbálník, Angela Hewitt, Greg Worrell, Matt Stead
BACKGROUND: High frequency oscillations (HFOs) are emerging as potentially clinically important biomarkers for localizing seizure generating regions in epileptic brain. These events, however, are too frequent, and occur on too small a time scale to be identified quickly or reliably by human reviewers. Many of the deficiencies of the HFO detection algorithms published to date are addressed by the CS algorithm presented here. NEW METHOD: The algorithm employs novel methods for: 1) normalization; 2) storage of parameters to model human expertise; 3) differentiating highly localized oscillations from filtering phenomena; and 4) defining temporal extents of detected events...
August 28, 2017: Journal of Neuroscience Methods
https://www.readbyqxmd.com/read/28794978/localization-of-beta-and-high-frequency-oscillations-within-the-subthalamic-nucleus-region
#3
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/28748408/a-simple-statistical-method-for-the-automatic-detection-of-ripples-in-human-intracranial-eeg
#4
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/28718452/role-of-al-doping-in-the-filament-disruption-in-hfo2-resistance-switches
#5
Stefano Brivio, Jacopo Frascaroli, Sabina Spiga
Resistance switching devices, whose operation is driven by formation (SET) and dissolution (RESET) of conductive paths shorting and disconnecting the two metal electrodes, have recently received great attention and a deep general comprehension of their operation has been achieved. However, the link between switching characteristics and material properties is still quite weak. In particular, doping of the switching oxide layer has often been investigated only for looking at performance upgrade and rarely for a meticulous investigation of the switching mechanism...
July 18, 2017: Nanotechnology
https://www.readbyqxmd.com/read/28709992/time-dependent-evolution-of-seizures-in-a-model-of-mesial-temporal-lobe-epilepsy
#6
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...
October 2017: Neurobiology of Disease
https://www.readbyqxmd.com/read/28681378/update-on-the-mechanisms-and-roles-of-high-frequency-oscillations-in-seizures-and-epileptic-disorders
#7
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...
August 2017: Epilepsia
https://www.readbyqxmd.com/read/28676240/local-nmda-receptor-hypofunction-evokes-generalized-effects-on-gamma-and-high-frequency-oscillations-and-behavior
#8
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/28669244/automated-detector-of-high-frequency-oscillations-in-epilepsy-based-on-maximum-distributed-peak-points
#9
Guo-Ping Ren, Jia-Qing Yan, Zhi-Xin Yu, Dan Wang, Xiao-Nan Li, Shan-Shan Mei, Jin-Dong Dai, Xiao-Li Li, Yun-Lin Li, Xiao-Fei Wang, Xiao-Feng Yang
High frequency oscillations (HFOs) are considered as biomarker for epileptogenicity. Reliable automation of HFOs detection is necessary for rapid and objective analysis, and is determined by accurate computation of the baseline. Although most existing automated detectors measure baseline accurately in channels with rare HFOs, they lose accuracy in channels with frequent HFOs. Here, we proposed a novel algorithm using the maximum distributed peak points method to improve baseline determination accuracy in channels with wide HFOs activity ranges and calculate a dynamic baseline...
April 17, 2017: International Journal of Neural Systems
https://www.readbyqxmd.com/read/28666056/high-frequency-oscillations-the-state-of-clinical-research
#10
REVIEW
Birgit Frauscher, Fabrice Bartolomei, Katsuhiro Kobayashi, Jan Cimbalnik, Maryse A van 't Klooster, Stefan Rampp, Hiroshi Otsubo, Yvonne Höller, Joyce Y Wu, Eishi Asano, Jerome Engel, Philippe Kahane, Julia Jacobs, Jean Gotman
Modern electroencephalographic (EEG) technology contributed to the appreciation that the EEG signal outside the classical Berger frequency band contains important information. In epilepsy, research of the past decade focused particularly on interictal high-frequency oscillations (HFOs) > 80 Hz. The first large application of HFOs was in the context of epilepsy surgery. This is now followed by other applications such as assessment of epilepsy severity and monitoring of antiepileptic therapy. This article reviews the evidence on the clinical use of HFOs in epilepsy with an emphasis on the latest developments...
August 2017: Epilepsia
https://www.readbyqxmd.com/read/28631617/hfo2-high-k-solid-state-incandescent-devices-performance-improvement-using-a-ti-embedded-layer-and-observation-of-conductive-paths-as-light-emitting-sources
#11
Yiwei Liu, Can Yang, Jinyan Zhao, Shengli Wu, Liyan Dai, Gang Niu
Solid-state incandescent light-emission devices (SSI-LEDs) with a metal-oxide-semiconductor structure are promising candidates for future broadband light-emission devices. In this work, the electrical and light-emission features of SSI-LEDs based on HfO2 high-k thin films with or without the Ti-embedded layer on p-type silicon wafers have been studied. It turns out that the Ti-embedded layer can effectively reduce the turn-on voltage, thus improving the fluorescence efficiency of SSI-LEDs. The combination of scanning electron microscopy, atomic force microscope (AFM) and conductive AFM results unambiguously clarifies that conductive filaments, which are formed due to local thermal excitation during the forming process, are accompanied by the formation of pits on the HfO2 surface and are responsible for the light emission...
June 20, 2017: Nanotechnology
https://www.readbyqxmd.com/read/28622421/how-to-record-high-frequency-oscillations-in-epilepsy-a-practical-guideline
#12
REVIEW
Maeike Zijlmans, Gregory A Worrell, Matthias Dümpelmann, Thomas Stieglitz, Andrei Barborica, Marcel Heers, Akio Ikeda, Naotaka Usui, Michel Le Van Quyen
OBJECTIVE: Technology for localizing epileptogenic brain regions plays a central role in surgical planning. Recent improvements in acquisition and electrode technology have revealed that high-frequency oscillations (HFOs) within the 80-500 Hz frequency range provide the neurophysiologist with new information about the extent of the epileptogenic tissue in addition to ictal and interictal lower frequency events. Nevertheless, two decades after their discovery there remain questions about HFOs as biomarkers of epileptogenic brain and there use in clinical practice...
August 2017: Epilepsia
https://www.readbyqxmd.com/read/28618715/retention-model-of-tao-hfo-x-and-tao-alo-x-rram-with-self-rectifying-switch-characteristics
#13
Yu-De Lin, Pang-Shiu Chen, Heng-Yuan Lee, Yu-Sheng Chen, Sk Ziaur Rahaman, Kan-Hsueh Tsai, Chien-Hua Hsu, Wei-Su Chen, Pei-Hua Wang, Ya-Chin King, Chrong Jung Lin
A retention behavior model for self-rectifying TaO/HfO x - and TaO/AlO x -based resistive random-access memory (RRAM) is proposed. Trapping-type RRAM can have a high resistance state (HRS) and a low resistance state (LRS); the degradation in a LRS is usually more severe than that in a HRS, because the LRS during the SET process is limited by the internal resistor layer. However, if TaO/AlO x elements are stacked in layers, the LRS retention can be improved. The LRS retention time estimated by extrapolation method is more than 5 years at room temperature...
December 2017: Nanoscale Research Letters
https://www.readbyqxmd.com/read/28549276/different-seizure-onset-patterns-in-mesiotemporal-lobe-epilepsy-have-a-distinct-interictal-signature
#14
Birgit Frauscher, Nicolás von Ellenrieder, François Dubeau, Jean Gotman
OBJECTIVE: Experimental research demonstrated that distinct underlying mechanisms go along with different seizure-onset patterns on EEG. These different mechanisms may reflect different tissue abnormalities which, we hypothesize, could also be reflected in morphological differences in the interictal epileptic and background EEG activity. METHODS: We searched our database of intracranial EEG recordings for mesiotemporal lobe epilepsy patients with either predominant low-voltage fast activity (LVF) or periodic spiking (PS)...
July 2017: Clinical Neurophysiology: Official Journal of the International Federation of Clinical Neurophysiology
https://www.readbyqxmd.com/read/28548907/evaluation-of-thermal-optical-analysis-method-of-elemental-carbon-for-marine-fuel-exhaust
#15
Maija K Lappi, Jyrki P Ristimäki
The awareness of black carbon (BC) as the second largest anthropogenic contributor in global warming and an ice melting enhancer has increased. Due to prospected increase in shipping especially in the Arctic reliability of BC emissions and their invented amounts from ships is gaining more attention. The International Maritime Organisation (IMO) is actively working towards estimation of quantities and effects of BC especially in the Arctic. IMO has launched work towards constituting a definition for BC and agreeing appropriate methods for its determination from shipping emission sources...
May 26, 2017: Journal of the Air & Waste Management Association
https://www.readbyqxmd.com/read/28535957/improving-oil-classification-quality-from-oil-spill-fingerprint-beyond-six-sigma-approach
#16
Hafizan Juahir, Azimah Ismail, Saiful Bahri Mohamed, Mohd Ekhwan Toriman, Azlina Md Kassim, Sharifuddin Md Zain, Wan Kamaruzaman Wan Ahmad, Wong Kok Wah, Munirah Abdul Zali, Ananthy Retnam, Mohd Zaki Mohd Taib, Mazlin Mokhtar
This study involves the use of quality engineering in oil spill classification based on oil spill fingerprinting from GC-FID and GC-MS employing the six-sigma approach. The oil spills are recovered from various water areas of Peninsular Malaysia and Sabah (East Malaysia). The study approach used six sigma methodologies that effectively serve as the problem solving in oil classification extracted from the complex mixtures of oil spilled dataset. The analysis of six sigma link with the quality engineering improved the organizational performance to achieve its objectivity of the environmental forensics...
May 20, 2017: Marine Pollution Bulletin
https://www.readbyqxmd.com/read/28521267/epileptogenic-high-frequency-oscillations-skip-the-motor-area-in-children-with-multilobar-drug-resistant-epilepsy
#17
Yasushi Iimura, Kevin Jones, Kyoko Hattori, Yushi Okazawa, Atsuko Noda, Kana Hoashi, Yutaka Nonoda, Eishi Asano, Tomoyuki Akiyama, Cristina Go, Ayako Ochi, O Carter Snead, Elizabeth J Donner, James T Rutka, James M Drake, Hiroshi Otsubo
OBJECTIVE: Subtotal hemispherectomy involves the resection of multiple lobes in children with drug-resistant epilepsy, skipping the motor area (MA). We determined epileptogenicity using the occurrence rate (OR) of high-frequency oscillations (HFOs) and the modulation index (MI), demonstrating strength of coupling between HFO and slow wave. We hypothesized that epileptogenicity increased over the multiple lobes but skipped the MA. METHODS: We analyzed 23 children (14 subtotal hemispherectomy; 9 multilobar resections)...
July 2017: Clinical Neurophysiology: Official Journal of the International Federation of Clinical Neurophysiology
https://www.readbyqxmd.com/read/28499085/simultaneous-oxidation-and-sequestration-of-as-iii-from-water-by-using-redox-polymer-based-fe-iii-oxide-nanocomposite
#18
Xiaolin Zhang, Mengfei Wu, Hao Dong, Hongchao Li, Bingcai Pan
Water decontamination from As(III) is an urgent but still challenging task. Herein, we fabricated a bifunctional nanocomposite HFO@PS-Cl for highly efficient removal of As(III), with active chlorine covalently binding spherical polystyrene host for in situ oxidation of As(III) to As(V), and Fe(III) hydroxide (HFO) nanoparticles (NPs) embedded inside for specific As(V) removal. HFO@PS-Cl could work effectively in a wide pH range (5-9), and other substances like sulfate, chloride, bicarbonate, silicate, and humic acid exert insignificant effect on As(III) removal...
June 6, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28463818/high-frequency-somatosensory-stimulation-increases-sensori-motor-inhibition-and-leads-to-perceptual-improvement-in-healthy-subjects
#19
Lorenzo Rocchi, Roberto Erro, Elena Antelmi, Alfredo Berardelli, Michele Tinazzi, Rocco Liguori, Kailash Bhatia, John Rothwell
OBJECTIVE: High frequency repetitive somatosensory stimulation (HF-RSS), which is a patterned electric stimulation applied to the skin through surface electrodes, improves two-point discrimination, somatosensory temporal discrimination threshold (STDT) and motor performance in humans. However, the mechanisms which underlie these changes are still unknown. In particular, we hypothesize that refinement of inhibition might be responsible for the improvement in spatial and temporal perception...
June 2017: Clinical Neurophysiology: Official Journal of the International Federation of Clinical Neurophysiology
https://www.readbyqxmd.com/read/28451519/a-longitudinal-ecological-study-of-household-firearm-ownership-and-firearm-related-deaths-in-the-united-states-from-1999-through-2014-a-specific-focus-on-gender-race-and-geographic-variables
#20
David A Geier, Janet K Kern, Mark R Geier
Firearms have a longstanding tradition in the United States (US) and are viewed by many with iconic stature with regards to safety and personal freedom. Unfortunately, from a public health point of view, firearm-related deaths (FRDs) in the US have reached a crisis point with an estimated > 31,000 deaths and 74,000 nonfatal injuries resulting from firearms each year. This longitudinal ecological study analyzed variations in FRDs following firearm assaults (FAs) and law enforcement incidents involving a firearm (LEIF) in comparison to variations in household firearm ownership (HFO) among different geographic and demographic groups in the US from 1999 to 2014...
June 2017: Preventive Medicine Reports
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