23,371 results match your criteria electrical channels

The effects of beta-cell mass and function, intercellular coupling, and islet synchrony on [Formula: see text] dynamics.

Sci Rep 2021 May 13;11(1):10268. Epub 2021 May 13.

Biomathematics Laboratory, Department of Applied Mathematics, School of Mathematical Sciences, Tarbiat Modares University, Tehran, Iran.

Type 2 diabetes (T2D) is a challenging metabolic disorder characterized by a substantial loss of [Formula: see text]-cell mass and alteration of [Formula: see text]-cell function in the islets of Langerhans, disrupting insulin secretion and glucose homeostasis. The mechanisms for deficiency in [Formula: see text]-cell mass and function during the hyperglycemia development and T2D pathogenesis are complex. To study the relative contribution of [Formula: see text]-cell mass to [Formula: see text]-cell function in T2D, we make use of a comprehensive electrophysiological model of human [Formula: see text]-cell clusters. Read More

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Compact and fast depth sensor based on a liquid lens using chromatic aberration to improve accuracy.

Opt Express 2021 May;29(10):15786-15801

Depth from defocus (DFD) obtains depth information using two defocused images, making it possible to obtain a depth map with high resolution equal to that of the RGB image. However, it is difficult to change the focus mechanically in real-time applications, and the depth range is narrow because it is inversely proportional to the depth accuracy. This paper presents a compact DFD system based on a liquid lens that uses chromatic aberration for real-time application and depth accuracy improvement. Read More

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Agnostic sampling transceiver.

Opt Express 2021 May;29(10):14828-14840

Increasing demands for data centers, backbone, access, and wireless networks require inventive concepts to transmit and distribute digital or analog signal waveforms. We present a new, extremely simple transceiver concept, fundamentally different from conventional approaches. It does not rely on high-speed electronics and enables transmission of various time multiplexed analog waveforms or digital data signals with the maximum possible symbol rate in the same rectangular optical spectral band B. Read More

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Automated accurate emotion recognition system using rhythm-specific deep convolutional neural network technique with multi-channel EEG signals.

Comput Biol Med 2021 May 6;134:104428. Epub 2021 May 6.

Department of Electronics and Computer Engineering, Ngee Ann Polytechnic, Singapore; Department of Bioinformatics and Medical Engineering, Asia University, Taichung, Taiwan; International Research Organization for Advanced Science and Technology, Kumamoto University, Kumamoto, Japan.

Emotion is interpreted as a psycho-physiological process, and it is associated with personality, behavior, motivation, and character of a person. The objective of affective computing is to recognize different types of emotions for human-computer interaction (HCI) applications. The spatiotemporal brain electrical activity is measured using multi-channel electroencephalogram (EEG) signals. Read More

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Microstimulation-evoked neural responses in visual cortex are depth dependent.

Brain Stimul 2021 May 8. Epub 2021 May 8.

Department of Physiology and Biomedicine Discovery Institute, Monash University, Clayton, Vic, 3800, Australia; ARC Centre of Excellence for Integrative Brain Function, Australia; Department of Electrical and Computer Systems Engineering, Monash University, Clayton, Vic, 3800, Australia; Monash Vision Group, Monash University, Clayton, Vic, 3800, Australia. Electronic address:

Background: Cortical visual prostheses often use penetrating electrode arrays to deliver microstimulation to the visual cortex. To optimize electrode placement within the cortex, the neural responses to microstimulation at different cortical depths must first be understood.

Objective: We investigated how the neural responses evoked by microstimulation in cortex varied with cortical depth, of both stimulation and response. Read More

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Constructing ion channels from water-soluble α-helical barrels.

Nat Chem 2021 May 10. Epub 2021 May 10.

School of Chemistry, University of Bristol, Bristol, UK.

The design of peptides that assemble in membranes to form functional ion channels is challenging. Specifically, hydrophobic interactions must be designed between the peptides and at the peptide-lipid interfaces simultaneously. Here, we take a multi-step approach towards this problem. Read More

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Responsive manipulation of neural circuit pathology by fully implantable, front-end multiplexed embedded neuroelectronics.

Proc Natl Acad Sci U S A 2021 May;118(20)

Department of Electrical Engineering, Columbia University, New York, NY 10027;

Responsive neurostimulation is increasingly required to probe neural circuit function and treat neuropsychiatric disorders. We introduce a multiplex-then-amplify (MTA) scheme that, in contrast to current approaches (which necessitate an equal number of amplifiers as number of channels), only requires one amplifier per multiplexer, significantly reducing the number of components and the size of electronics in multichannel acquisition systems. It also enables simultaneous stimulation of arbitrary waveforms on multiple independent channels. Read More

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Detecting pollutant sources and pathways: High-frequency automated online monitoring in a small rural French/German transborder catchment.

J Environ Manage 2021 May 7;290:112619. Epub 2021 May 7.

Institute of Inorganic and Analytical Chemistry, Saarland University, Dudweiler Zeile 4, 66125, Saarbruecken, Germany.

Great temporal and spatial variability of inputs make comprehensive monitoring in small and middle sized rivers difficult. In this study, relevant inputs in a small river were recorded with suitable online monitoring equipment coupled in mobile water quality monitoring stations, the study area being a transborder catchment with French and German (Saarland federal state) subcatchments. In addition to a pronounced spatial variability necessitating a denser net of measuring points this catchment has also to be assessed in the light of different national regulations. Read More

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High-Capacity Cardiac Signal Acquisition System for Flexible, Simultaneous, Multidomain Acquisition.

Comput Cardiol (2010) 2020 Sep 10;47. Epub 2021 Feb 10.

Scientific Computing and Imaging Institute, SLC, USA.

Capturing cardiac electrical propagation or electrocardiographic images demands simultaneous, multidomain recordings of electrocardiographic signals with adequate spatial and temporal resolution. Available systems can be cost-prohibitive or lack the necessary flexibility to capture signals from the heart and torso. We have designed and constructed a system that leverages affordable commercial products (Intantech, CA, USA) to create a complete, cardiac signal acquisition system that includes a flexible front end, analog signal conditioning, and defibrillation protection. Read More

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September 2020

FBSED based automatic diagnosis of COVID-19 using X-ray and CT images.

Comput Biol Med 2021 May 2;134:104454. Epub 2021 May 2.

Department of Electrical Engineering, Indian Institute of Technology Indore, Indore, 453552, India. Electronic address:

This work introduces the Fourier-Bessel series expansion-based decomposition (FBSED) method, which is an implementation of the wavelet packet decomposition approach in the Fourier-Bessel series expansion domain. The proposed method has been used for the diagnosis of pneumonia caused by the 2019 novel coronavirus disease (COVID-19) using chest X-ray image (CXI) and chest computer tomography image (CCTI). The FBSED method is used to decompose CXI and CCTI into sub-band images (SBIs). Read More

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Involvement of TRPV1 and TRPA1 in the modulation of pacemaker potentials in the mouse ileum.

Cell Calcium 2021 Apr 30;97:102417. Epub 2021 Apr 30.

School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China.

Background: The roles of transient receptor potential cation channel, subfamily V, member 1 (TRPV1) and subfamily A, member 1 (TRPA1) in mechanisms of gastrointestinal motility are complex. This study aimed to clarify the effects of several TRPV1 and TRPA1 ligands on the electrical potentials generated by pacemaker cells in the mouse-isolated ileum.

Method: The pacemaker potentials of ileal segments of mice were recorded extracellularly using a 60-channel microelectrode array. Read More

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SynCells: A 60 × 60 μm Electronic Platform with Remote Actuation for Sensing Applications in Constrained Environments.

ACS Nano 2021 May 7. Epub 2021 May 7.

Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States.

Autonomous electronic microsystems smaller than the diameter of a human hair (<100 μm) are promising for sensing in confined spaces such as microfluidic channels or the human body. However, they are difficult to implement due to fabrication challenges and limited power budget. Here we present a 60 × 60 μm electronic microsystem platform, or SynCell, that overcomes these issues by leveraging the integration capabilities of two-dimensional material circuits and the low power consumption of passive germanium timers, memory-like chemical sensors, and magnetic pads. Read More

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On Local Activity and Edge of Chaos in a NaMLab Memristor.

Front Neurosci 2021 20;15:651452. Epub 2021 Apr 20.

Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, Berkeley, CA, United States.

Local activity is the capability of a system to amplify infinitesimal fluctuations in energy. Complex phenomena, including the generation of action potentials in neuronal axon membranes, may never emerge in an open system unless some of its constitutive elements operate in a locally active regime. As a result, the recent discovery of solid-state volatile memory devices, which, biased through appropriate DC sources, may enter a local activity domain, and, most importantly, the associated stable yet excitable sub-domain, referred to as edge of chaos, which is where the seed of complexity is actually planted, is of great appeal to the neuromorphic engineering community. Read More

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Mitochondrial calcium uniporter is essential for hearing and hair cell preservation in congenic FVB/NJ mice.

Sci Rep 2021 May 6;11(1):9660. Epub 2021 May 6.

Department of Otolaryngology-Head and Neck Surgery, School of Medicine, Case Western Reserve University and University Hospitals Cleveland Medical Center, 11100 Euclid Ave., Cleveland, OH, 44106, USA.

Mitochondrial Ca regulates a wide range of cell processes, including morphogenesis, metabolism, excitotoxicity, and survival. In cochlear hair cells, the activation of mechano-electrical transduction and voltage-gated Ca channels result in a large influx of Ca. The intracellular rise in Ca is partly balanced by the mitochondria which rapidly uptakes Ca via a highly selective channel comprised of the main pore-forming subunit, the mitochondrial Ca uniporter (MCU), and associated regulatory proteins. Read More

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Acoustic-Field Beamforming for Low-Power Portable Ultrasound.

Ultrason Imaging 2021 May 6:1617346211013473. Epub 2021 May 6.

Department of Electrical Engineering, National Tsing Hua University, Hsinchu.

Portable ultrasound has been extensively used for diagnostic applications in health monitoring, emergency rooms, and ambulances. However, these handheld ultrasound systems may suffer from heat and battery issues attributed to the large power consumption of the transmitter. Additionally, the largest portion of the direct current (DC) power consumption can be attributed to the amplifier in the digital-to-analog converter (DAC) of the transmitter and to the analog-to-digital converter (ADC) of the receiver. Read More

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Hexachromatic bioinspired camera for image-guided cancer surgery.

Sci Transl Med 2021 May;13(592)

Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.

Cancer affects one in three people worldwide. Surgery remains the primary curative option for localized cancers, but good prognoses require complete removal of primary tumors and timely recognition of metastases. To expand surgical capabilities and enhance patient outcomes, we developed a six-channel color/near-infrared image sensor inspired by the mantis shrimp visual system that enabled near-infrared fluorescence image guidance during surgery. Read More

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3D Printed Porous Methacrylate/Silica Hybrid Scaffold for Bone Substitution.

Adv Healthc Mater 2021 May 5:e2100117. Epub 2021 May 5.

Department of Materials, Imperial College London, London, SW7 2AZ, United Kingdom.

Inorganic-organic hybrid biomaterials made with star polymer poly(methyl methacrylate-co-3-(trimethoxysilyl)propyl methacrylate) and silica which show promising mechanical properties, are 3D printed as bone substitutes for the first time, by direct ink writing of the sol. Three different inorganic:organic ratios of poly(methyl methacrylate-co-3-(trimethoxysilyl)propyl methacrylate)-star-SiO hybrid inks are printed with pore channels in the range of 100-200 µm. Mechanical properties of the 3D printed scaffolds fall within the range of trabecular bone, and MC3T3 pre-osteoblast cells are able to adhere to the scaffolds in vitro, regardless of their compositions. Read More

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Confinement and Protection of Skyrmions by Patterns of Modified Magnetic Properties.

Nano Lett 2021 May 5. Epub 2021 May 5.

Department of Electrical and Computer Engineering, Shinshu University, 4-17-1 Wakasato, Nagano 380-8553, Japan.

Magnetic skyrmions are versatile topological excitations that can be used as nonvolatile information carriers. The confinement of skyrmions in channels is fundamental for any application based on the accumulation and transport of skyrmions. Here, we report a method that allows effective position control of skyrmions in designed channels by engineered energy barriers and wells, which is realized in a magnetic multilayer film by harnessing the boundaries of patterns with modified magnetic properties. Read More

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Reference Electrode Standardization Interpolation Technique (RESIT): A Novel Interpolation Method for Scalp EEG.

Brain Topogr 2021 May 5. Epub 2021 May 5.

The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, China.

"Bad channels" are common phenomena during scalp electroencephalography (EEG) recording that arise due to various technique-related reasons, and reconstructing signals from bad channels is an inevitable choice in EEG processing. However, current interpolation methods are all based on purely mathematical interpolation theory, ignoring the neurophysiological basis of the EEG signals, and their performance needs to be further improved, especially when there are many scattered or adjacent bad channels. Therefore, a new interpolation method, named the reference electrode standardization interpolation technique (RESIT), was developed for interpolating scalp EEG channels. Read More

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Using Direct Acyclic Graphs to Enhance Skeleton-Based Action Recognition with a Linear-Map Convolution Neural Network.

Sensors (Basel) 2021 Apr 29;21(9). Epub 2021 Apr 29.

Department of Computer Science & Software Engineering, College of Information Technology, United Arab Emirates University, Al Ain P.O. Box 15551, Abu Dhabi, United Arab Emirates.

Research on the human activity recognition could be utilized for the monitoring of elderly people living alone to reduce the cost of home care. Video sensors can be easily deployed in the different zones of houses to achieve monitoring. The goal of this study is to employ a linear-map convolutional neural network (CNN) to perform action recognition with RGB videos. Read More

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Regulation of Cardiac Conduction and Arrhythmias by Ankyrin/Spectrin-Based Macromolecular Complexes.

J Cardiovasc Dev Dis 2021 Apr 29;8(5). Epub 2021 Apr 29.

The Frick Center for Heart Failure and Arrhythmia, The Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA.

The cardiac conduction system is an extended network of excitable tissue tasked with generation and propagation of electrical impulses to signal coordinated contraction of the heart. The fidelity of this system depends on the proper spatio-temporal regulation of ion channels in myocytes throughout the conduction system. Importantly, inherited or acquired defects in a wide class of ion channels has been linked to dysfunction at various stages of the conduction system resulting in life-threatening cardiac arrhythmia. Read More

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Effects of electromagnetic fields on neuronal ion channels: a systematic review.

Ann N Y Acad Sci 2021 May 4. Epub 2021 May 4.

Leverhulme Quantum Biology Doctoral Training Centre, University of Surrey, Guildford, Surrey, UK.

Many aspects of chemistry and biology are mediated by electromagnetic field (EMF) interactions. The central nervous system (CNS) is particularly sensitive to EMF stimuli. Studies have explored the direct effect of different EMFs on the electrical properties of neurons in the last two decades, particularly focusing on the role of voltage-gated ion channels (VGCs). Read More

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A Phase 1 Study to Investigate the Effects of Cortexolone 17α-Propionate, Also Known as Clascoterone, on the QT Interval Using the Meal Effect to Demonstrate ECG Assay Sensitivity.

Clin Pharmacol Drug Dev 2021 May 3. Epub 2021 May 3.

St George's, University of London, London, United Kingdom.

Cortexolone 17α-propionate, also known as clascoterone, is a potent androgen receptor inhibitor intended for the topical treatment of skin diseases associated with androgenic pathway alterations. In nonclinical studies, cortexolone 17α-propionate was found to have a weak inhibitory effect on human Ether-à-go-go-Related Gene (hERG) potassium channels, which are vital for normal electrical activity in the heart. When used in a cream formulation, little cortexolone 17α-propionate is absorbed. Read More

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The voltage sensor is responsible for ΔpH dependence in H1 channels.

Proc Natl Acad Sci U S A 2021 May;118(19)

Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, 2351319 Valparaíso, Chile;

The dissipation of acute acid loads by the voltage-gated proton channel (H1) relies on regulating the channel's open probability by the voltage and the ΔpH across the membrane (ΔpH = pH - pH). Using monomeric -H1, we asked whether ΔpH-dependent gating is produced during the voltage sensor activation or permeation pathway opening. A leftward shift of the conductance-voltage (G-V) curve was produced at higher ΔpH values in the monomeric channel. Read More

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Speech recognition as a function of the number of channels for an array with large inter-electrode distances.

J Acoust Soc Am 2021 Apr;149(4):2752

Department of Hearing and Speech Sciences, Vanderbilt University Medical Center, 1215 21st Avenue South, Nashville, Tennessee 37232, USA.

This study investigated the number of channels available to cochlear implant (CI) recipients for maximum speech understanding and sound quality for lateral wall electrode arrays-which result in large electrode-to-modiolus distances-featuring the greatest inter-electrode distances (2.1-2.4 mm), the longest active lengths (23. Read More

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Local and Distant responses to single pulse electrical stimulation reflect different forms of connectivity.

Neuroimage 2021 Apr 30:118094. Epub 2021 Apr 30.

Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, USA; Nayef Al-Rodhan Laboratories, Department of Neurosurgery, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA. Electronic address:

Measuring connectivity in the human brain involves innumerable approaches using both noninvasive (fMRI, EEG) and invasive (intracranial EEG or iEEG) recording modalities, including the use of external probing stimuli, such as direct electrical stimulation. To examine how different measures of connectivity correlate with one another, we compared 'passive' measures of connectivity during resting state conditions to the more 'active' probing measures of connectivity with single pulse electrical stimulation (SPES). We measured the network engagement and spread of the cortico-cortico evoked potential (CCEP) induced by SPES at 53 out of 104 total sites across the brain, including cortical and subcortical regions, in patients with intractable epilepsy (N=11) who were undergoing intracranial recordings as a part of their clinical care for identifying seizure onset zones. Read More

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Rutaecarpine targets hERG channels and participates in regulating electrophysiological properties leading to ventricular arrhythmia.

J Cell Mol Med 2021 May 3. Epub 2021 May 3.

Department of Pharmacology (State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, Key Laboratory of Cardiovascular Medicine Research, Ministry of Education), College of Pharmacy, Harbin Medical University, Harbin, China.

Drug-mediated or medical condition-mediated disruption of hERG function accounts for the main cause of acquired long-QT syndrome (acLQTs), which predisposes affected individuals to ventricular arrhythmias (VA) and sudden death. Many Chinese herbal medicines, especially alkaloids, have risks of arrhythmia in clinical application. The characterized mechanisms behind this adverse effect are frequently associated with inhibition of cardiac hERG channels. Read More

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Electric-Field-Induced Neural Precursor Cell Differentiation in Microfluidic Devices.

J Vis Exp 2021 Apr 14(170). Epub 2021 Apr 14.

Research Center for Applied Sciences, Academia Sinica; Institute of Biophotonics, National Yang Ming Chao Tung University; Department of Mechanical and Mechatronic Engineering, National Taiwan Ocean University; College of Engineering, Chang Gung University;

Physiological electric fields (EF) play vital roles in cell migration, differentiation, division, and death. This paper describes a microfluidic cell culture system that was used for a long-term cell differentiation study using microscopy. The microfluidic system consists of the following major components: an optically transparent electrotactic chip, a transparent indium-tin-oxide (ITO) heater, a culture media-filling pump, an electrical power supply, a high-frequency power amplifier, an EF multiplexer, a programmable X-Y-Z motorized stage, and an inverted phase-contrast microscope equipped with a digital camera. Read More

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Optimization of Thermal and Structural Design in Lithium-Ion Batteries to Obtain Energy Efficient Battery Thermal Management System (BTMS): A Critical Review.

Arch Comput Methods Eng 2021 Apr 26:1-66. Epub 2021 Apr 26.

Department of Mechanical Engineering, College of Engineering, King Khalid University, PO Box 394, Abha, 61421 Saudi Arabia.

Covid-19 has given one positive perspective to look at our planet earth in terms of reducing the air and noise pollution thus improving the environmental conditions globally. This positive outcome of pandemic has given the indication that the future of energy belong to green energy and one of the emerging source of green energy is Lithium-ion batteries (LIBs). LIBs are the backbone of the electric vehicles but there are some major issues faced by the them like poor thermal performance, thermal runaway, fire hazards and faster rate of discharge under low and high temperature environment,. Read More

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Acute effects of brain-responsive neurostimulation in drug-resistant partial onset epilepsy.

Clin Neurophysiol 2021 Mar 31. Epub 2021 Mar 31.

NeuroPace, Inc., Mountain View, CA, USA.

Objective: Understanding the acute effects of responsive stimulation (AERS) based on intracranial EEG (iEEG) recordings in ambulatory patients with drug-resistant partial epilepsy, and correlating these with changes in clinical seizure frequency, may help clinicians more efficiently optimize responsive stimulation settings.

Methods: In patients implanted with the NeuroPace® RNS® System, acute changes in iEEG spectral power following active and sham stimulation periods were quantified and compared within individual iEEG channels. Additionally, acute stimulation-induced acute iEEG changes were compared within iEEG channels before and after patients experienced substantial reductions in clinical seizure frequency. Read More

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