255,106 results match your criteria channels

The insecticidal activity of recombinant nemertide toxin α-1 from Lineus longissimus towards pests and beneficial species.

Toxicon 2021 Apr 11. Epub 2021 Apr 11.

Durham University, Department of Biosciences, Stockton Rd, Durham, DH1 3LE, UK.

The nemertide toxins from the phylum Nemertea are a little researched family of neurotoxins with potential for development as biopesticides. Here we report the recombinant production of nemertide α-1 (α-1), a 65-residue inhibitor cystine knot (ICK) peptide from Lineus longissimus, known to target insect voltage-gated sodium channels. The insecticidal activity of α-1 was assessed and compared with the well characterised ICK venom peptide, ω-atracotoxin/hexatoxin-Hv1a (Hv1a). Read More

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Differential contributions of voltage-gated potassium channel subunits in enhancing temporal coding in the bushy cells of the ventral cochlear nucleus.

J Neurophysiol 2021 Apr 14. Epub 2021 Apr 14.

Department of Physiology, School of Basic Medical Sciences, Southern Medical University, China.

Temporal coding precision of bushy cells in the ventral cochlear nucleus (VCN), critical for sound localization and communication, depends on the generation of rapid and temporally precise action potentials (APs). Voltage-gated potassium (Kv) channels are critically involved in this. The bushy cells in rat VCN express Kv1. Read More

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Marine communities of the newly created Kawésqar National Reserve, Chile: From glaciers to the Pacific Ocean.

PLoS One 2021 14;16(4):e0249413. Epub 2021 Apr 14.

Pristine Seas, National Geographic Society, Washington, DC, United States of America.

The newly created Kawésqar National Park (KNP) and National Reserve (KNR) in southern Chile consists of diverse terrestrial and marine habitats, which includes the southern terminus of the Andes, the Southern Patagonia Ice Fields, sub-Antarctic rainforests, glaciers, fjords, lakes, wetlands, valleys, channels, and islands. The marine environment is influenced by wide ranging hydrological factors such as glacier melt, large terrigenous inputs, high precipitation, strong currents, and open ocean water masses. Owing to the remoteness, rugged terrain, and harsh environmental conditions, little is known about this vast region, particularly the marine realm. Read More

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Differential contributions of synaptic and intrinsic inhibitory currents to speech segmentation via flexible phase-locking in neural oscillators.

PLoS Comput Biol 2021 Apr 14;17(4):e1008783. Epub 2021 Apr 14.

Department of Mathematics & Statistics, Boston University, Boston, Massachusetts, United States of America.

Current hypotheses suggest that speech segmentation-the initial division and grouping of the speech stream into candidate phrases, syllables, and phonemes for further linguistic processing-is executed by a hierarchy of oscillators in auditory cortex. Theta (∼3-12 Hz) rhythms play a key role by phase-locking to recurring acoustic features marking syllable boundaries. Reliable synchronization to quasi-rhythmic inputs, whose variable frequency can dip below cortical theta frequencies (down to ∼1 Hz), requires "flexible" theta oscillators whose underlying neuronal mechanisms remain unknown. Read More

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Simultaneous State and Unknown Input Estimation for Complex Networks With Redundant Channels Under Dynamic Event-Triggered Mechanisms.

IEEE Trans Neural Netw Learn Syst 2021 Apr 14;PP. Epub 2021 Apr 14.

This article addresses the simultaneous state and unknown input estimation problem for a class of discrete time-varying complex networks (CNs) under redundant channels and dynamic event-triggered mechanisms (ETMs). The redundant channels, modeled by an array of mutually independent Bernoulli distributed stochastic variables, are exploited to enhance transmission reliability. For energy-saving purposes, a dynamic event-triggered transmission scheme is enforced to ensure that every sensor node sends its measurement to the corresponding estimator only when a certain condition holds. Read More

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SSVEP-Based Brain-Computer Interface with a Limited Number of Frequencies based on Dual-Frequency Biased Coding.

IEEE Trans Neural Syst Rehabil Eng 2021 Apr 14;PP. Epub 2021 Apr 14.

How to encode as many targets as possible with a limited-frequency resource is a difficult problem in the practical use of a steady-state visual evoked potential (SSVEP) based brain-computer interface (BCI) speller. To solve this problem, this study developed a novel method called dual-frequency biased coding (DFBC) to tag targets in a SSVEP-based 48-character virtual speller, in which each target is encoded with a permutation sequence consisting of two permuted flickering periods that flash at different frequencies. The proposed paradigm was validated by 11 participants in an offline experiment and 7 participants in an online experiment. Read More

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Activation of KCNQ (K7) K channels in enteric neurons inhibits epithelial Cl secretion in mouse distal colon.

Am J Physiol Cell Physiol 2021 Apr 14. Epub 2021 Apr 14.

Department of Biochemistry, West Virginia University School of Medicine, Morgantown, West Virginia; Department of Medicine, West Virginia University School of Medicine, Morgantown, West Virginia, United States.

K7 (KCNQ) K channels are expressed in many neuronal populations, and play an important role in regulating membrane potential by generating a hyper-polarizing K current and decreasing cell excitability. However, the role of K7 channels in the neural regulation of intestinal epithelial Cl secretion is not known. Cl secretion in mouse distal colon was measured as a function of short circuit current (I), while pharmacological approaches were used to test the hypothesis that activation of K7 channels in enteric neurons would inhibit epithelial Cl secretion. Read More

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Ferritin with Atypical Ferroxidase Centers Takes B-Channels as the Pathway for Fe Uptake from .

Inorg Chem 2021 Apr 14. Epub 2021 Apr 14.

Institute of Molecular Science, Shanxi University, Taiyuan 030006, China.

Here, we present a 1.9 Å resolution crystal structure of ferritin, which reveals that its ferroxidase center is located on the inner surface of ferritin but not buried within the four-helix of each subunit. Such a ferroxidase center exhibits a lower iron oxidation activity as compared to the reported ferritin. Read More

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An arginine residue in the outer segment of hASIC1a TM1 affects both proton affinity and channel desensitization.

J Gen Physiol 2021 May;153(5)

Department of Basic Sciences, Tsinghua University School of Medicine, Beijing, China.

Acid-sensing ion channels (ASICs) respond to changes in pH in the central and peripheral nervous systems and participate in synaptic plasticity and pain perception. Understanding the proton-mediated gating mechanism remains elusive despite the of their structures in various conformational states. We report here that R64, an arginine located in the outer segment of the first transmembrane domain of all three isoforms of mammalian ASICs, markedly impacts the apparent proton affinity of activation and the degree of desensitization from the open and preopen states. Read More

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The emerging paradigm of calcium homeostasis as a new therapeutic target for protozoan parasites.

Med Res Rev 2021 Apr 13. Epub 2021 Apr 13.

Infectious Diseases, Mayo Clinic, Jacksonville, Florida, 32224, USA.

Calcium channels (CCs), a group of ubiquitously expressed membrane proteins, are involved in many pathophysiological processes of protozoan parasites. Our understanding of CCs in cell signaling, organelle function, cellular homeostasis, and cell cycle control has led to improved insights into their structure and functions. In this article, we discuss CCs characteristics of five major protozoan parasites Plasmodium, Leishmania, Toxoplasma, Trypanosoma, and Cryptosporidium. Read More

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Speech Perception with Noise Vocoding and Background Noise: An EEG and Behavioral Study.

Yue Dong Yan Gai

J Assoc Res Otolaryngol 2021 Apr 13. Epub 2021 Apr 13.

Biomedical Engineering, Parks College of Engineering, Aviation and Technology, Saint Louis University, 3507 Lindell Blvd, St Louis, MO, 63103, USA.

This study explored the physiological response of the human brain to degraded speech syllables. The degradation was introduced using noise vocoding and/or background noise. The goal was to identify physiological features of auditory-evoked potentials (AEPs) that may explain speech intelligibility. Read More

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Improving data quality in observational research studies: Report of the Cure Glomerulonephropathy (CureGN) network.

Contemp Clin Trials Commun 2021 Jun 17;22:100749. Epub 2021 Feb 17.

NYU Langone Health, Department of Pediatrics, Division of Nephrology, New York, NY, USA.

Background: High data quality is of crucial importance to the integrity of research projects. In the conduct of multi-center observational cohort studies with increasing types and quantities of data, maintaining data quality is challenging, with few published guidelines.

Methods: The Cure Glomerulonephropathy (CureGN) Network has established numerous quality control procedures to manage the 70 participating sites in the United States, Canada, and Europe. Read More

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Liddle Syndrome due to a Novel c.1713 Deletion in the Epithelial Sodium Channel β-Subunit in a Normotensive Adolescent.

AACE Clin Case Rep 2021 Jan-Feb;7(1):65-68. Epub 2020 Dec 28.

College of Medicine, California Northstate University, Elk Grove, California.

Objective: Liddle syndrome (LS) is a rare autosomal dominant condition secondary to a gain-of-function mutation affecting the epithelial sodium channels (ENaCs) in the distal nephron. It presents with early-onset hypertension, hypokalemia, and metabolic alkalosis in the face of hyporeninemia and hypoaldosteronism. We report a novel mutation affecting the ENaCs in a normotensive adolescent with LS. Read More

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December 2020

Expert consensus of the Chinese Association for the Study of Pain on ion channel drugs for neuropathic pain.

World J Clin Cases 2021 Mar;9(9):2100-2109

Department of Algology, Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China.

Neuropathic pain (NPP) is a kind of pain caused by disease or damage impacting the somatosensory system. Ion channel drugs are the main treatment for NPP; however, their irregular usage leads to unsatisfactory pain relief. To regulate the treatment of NPP with ion channel drugs in clinical practice, the Chinese Association for the Study of Pain organized first-line pain management experts from China to write an expert consensus as the reference for the use of ion channels drugs . Read More

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Resveratrol sensitizes A549 cells to irradiation damage via suppression of store-operated calcium entry with Orai1 and STIM1 downregulation.

Exp Ther Med 2021 Jun 2;21(6):587. Epub 2021 Apr 2.

Department of Radiotherapy, Anhui Provincial Hospital, Hefei, Anhui 230031, P.R. China.

Resveratrol is a natural polyphenol with multiple positive biofunctions and was found to have potential as a radiosensitizer with an intricate molecular mechanism. Store-operated calcium entry (SOCE) is a novel intracellular calcium regulatory pattern that is mainly mediated by iron channels, such as by the stromal interaction molecule (STIM) and calcium release-activated calcium channel protein (Orai) families. SOCE was recently reported to be suppressed via the downregulation of STIM or Orai families for the promotion of tumor cell death induced by resveratrol. Read More

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Massive efflux of adenosine triphosphate into the extracellular space immediately after experimental traumatic brain injury.

Exp Ther Med 2021 Jun 31;21(6):575. Epub 2021 Mar 31.

Brain Injury Research Center, Department of Neurosurgery, David Geffen School of Medicine, University of California, LA 90095-6901, USA.

The aim of the current study was to determine effects of mild traumatic brain injury (TBI), with or without blockade of purinergic ATP Y1 (P2Y1) receptors or store-operated calcium channels, on extracellular levels of ATP, glutamate, glucose and lactate. Concentrations of ATP, glutamate, glucose and lactate were measured in cerebral microdialysis samples obtained from the ipsilateral cortex and underlying hippocampus of rats with mild unilateral controlled cortical impact (CCI) or sham injury. Immediately after CCI, a large release of ATP was observed in the cortex (3. Read More

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Broadband generation of perfect Poincaré beams via dielectric spin-multiplexed metasurface.

Nat Commun 2021 Apr 13;12(1):2230. Epub 2021 Apr 13.

National Laboratory of Solid-State Microstructures, Jiangsu Key Laboratory of Artificial Functional Materials, College of Engineering and Applied Sciences, Nanjing University, Nanjing, China.

The term Poincaré beam, which describes the space-variant polarization of a light beam carrying spin angular momentum (SAM) and orbital angular momentum (OAM), plays an important role in various optical applications. Since the radius of a Poincaré beam conventionally depends on the topological charge number, it is difficult to generate a stable and high-quality Poincaré beam by two optical vortices with different topological charge numbers, as the Poincaré beam formed in this way collapses upon propagation. Here, based on an all-dielectric metasurface platform, we experimentally demonstrate broadband generation of a generalized perfect Poincaré beam (PPB), whose radius is independent of the topological charge number. Read More

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Petasin and isopetasin reduce CGRP release from trigeminal afferents indicating an inhibitory effect on TRPA1 and TRPV1 receptor channels.

J Headache Pain 2021 Apr 13;22(1):23. Epub 2021 Apr 13.

Institute of Physiology and Pathophysiology, Friedrich-Alexander-University of Erlangen-Nürnberg, Universitätsstraße 17, 91054, Erlangen, Germany.

Background: Butterbur root extract with its active ingredients petasin and isopetasin has been used in the prophylactic treatment of migraine for years, while its sites of action are not completely clear. Calcitonin gene-related peptide (CGRP) is known as a biomarker and promoting factor of migraine. We set out to investigate the impact of petasins on the CGRP release from trigeminal afferents induced by activation of the calcium conducting transient receptor potential channels (TRPs) of the subtypes TRPA1 and TRPV1. Read More

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Cardiac-Specific Deletion of Orai3 Leads to Severe Dilated Cardiomyopathy and Heart Failure in Mice.

J Am Heart Assoc 2021 Apr 14:e019486. Epub 2021 Apr 14.

Department of Physiology University of Tennessee Health Science Center Memphis TN.

Background Orai3 is a mammalian-specific member of the Orai family (Orai1‒3) and a component of the store-operated Ca entry channels. There is little understanding of the role of Orai channels in cardiomyocytes, and its role in cardiac function remains unexplored. Thus, we developed mice lacking Orai1 and Orai3 to address their role in cardiac homeostasis. Read More

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Intrinsic Electrical Remodeling Underlies Atrioventricular Block in Athletes.

Circ Res 2021 Apr 14. Epub 2021 Apr 14.

Cardiovascular Sciences, University of Manchester, UNITED KINGDOM.

Athletes present with atrioventricular node (AV node) dysfunction manifesting as AV block. This can necessitate electronic pacemaker implantation, known to be more frequent in athletes with a long training history. AV block in athletes is attributed to high vagal tone. Read More

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Compensatory Usage of the Internet: The Case of Mukbang Watching on YouTube.

Psychiatry Investig 2021 Apr 15. Epub 2021 Apr 15.

International Gaming Research Unit, Psychology Department, Nottingham Trent University, Nottingham, UK.

Objective: Accumulating empirical research has emphasized that a wide range of online activities-such as using social networking sites-can be performed in order to compensate unattained needs or to cope with negative affect and psychopathological symptoms. Although the correlates of problematic social networking use have been extensively investigated, less is known about problematic YouTube use (PYU), an umbrella term grouping a number of different activities (e.g. Read More

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A skin-inspired soft material with directional mechanosensation.

Bioinspir Biomim 2021 Apr 13. Epub 2021 Apr 13.

College of Engineering, University of Georgia, Driftmier Engineering Center, 597 DW Brooks Drive, Athens, Georgia, 30602, UNITED STATES.

Lessons about artificial sensor design may be taken from evolutionarily perfected physiological systems. Mechanosensory cells in human skin are exquisitely sensitive to gentle touch and enable us to distinguish objects of different stiffnesses and textures. These cells are embedded in soft epidermal layers of gel-like consistency. Read More

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Separation of C/C binary organic gas mixtures via flexible nanoporous carbon molecular sieves: DFT calculations and MD simulations.

J Mol Graph Model 2021 Mar 30;106:107911. Epub 2021 Mar 30.

Institute of Atomic and Molecular Physics, Sichuan University, Chengdu, 610065, China.

The C/C hydrocarbon gas separation characteristics of nanoporous carbon molecular sieves (CMS) are studied using DFT calculations and MD simulations. To efficiently separate the equimolar CH/CH and CH/CH gas mixtures, CNT gas transport channels are embed between the polyphenylene membranes which created structural deformation for both CNT and membrane. The adsorption and permeation of gas molecules via CMS and the effect of nanochannel density and electric field on gas selectivity are analyzed. Read More

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Uranium integral fission product yields for a spectrally-shaped 14.1 MeV neutron source at the National Ignition Facility.

Appl Radiat Isot 2021 Apr 3;173:109711. Epub 2021 Apr 3.

Department of Engineering Physics, Air Force Institute of Technology, WPAFB, OH, 45433, USA.

This paper describes the experimental results for an energy tuning assembly created to modify the National Ignition Facility deuterium-tritium fusion neutron source into a notional thermonuclear and prompt fission neutron spectrum, which has applications in integral measurements, nuclear data benchmarks, and radiation effects on microelectronics. The Monte Carlo neutron transport utilized MCNP5 to estimate the ETA-modified fluence using the ENDF-B/VIII.0 and IRDFF-II continuous energy nuclear data libraries, and SCALE Sampler was used to estimate the systematic nuclear data covariance using ENDF-B/VII. Read More

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Porous ZrO encapsulated perovskite composite oxide for organic pollutants removal: Enhanced catalytic efficiency and suppressed metal leaching.

J Colloid Interface Sci 2021 Mar 31;596:455-467. Epub 2021 Mar 31.

School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, PR China. Electronic address:

Cobalt-based perovskite material, an effective activator of PMS, is widely employed for wastewater remediation, but still affected by the leakage of the cobalt ions. In this study, a porous core-shell structured perovskite LaFeCoO/SiO core @ZrO shell (LFCS@ZrO) was fabricated and partially etched to enlarge channels to further enhance mass transfer ability. The well-designed core-shell structure can not only restrain metal ion leaching by changing the surface microenvironment but also provide an additional driving force attributed to the enriched concentration gradient, thus enhancing the catalytic oxidation performance. Read More

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Attenuation of the extracellular matrix increases the number of synapses but suppresses synaptic plasticity through upregulation of SK channels.

Cell Calcium 2021 Apr 8;96:102406. Epub 2021 Apr 8.

Department of Molecular Neurobiology, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya Street 16/10, Moscow, 117997, Russia; Department of Physiology, Jiaxing University College of Medicine, Zhejiang, 314033 China; Sechenov First Moscow State Medical University, Bolshaya Pirogovskaya Str 19с1, Moscow, 119146, Russia. Electronic address:

The effect of brain extracellular matrix (ECM) on synaptic plasticity remains controversial. Here, we show that targeted enzymatic attenuation with chondroitinase ABC (ChABC) of ECM triggers the appearance of new glutamatergic synapses on hippocampal pyramidal neurons, thereby increasing the amplitude of field EPSPs while decreasing both the mean miniature EPSC amplitude and AMPA/NMDA ratio. Although the increased proportion of 'unpotentiated' synapses caused by ECM attenuation should promote long-term potentiation (LTP), surprisingly, LTP was suppressed. Read More

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TRPA1 channel: New kid in the 'neurovascular coupling' town.

Cell Calcium 2021 Apr 6;96:102407. Epub 2021 Apr 6.

Department of Pharmacology, University of Vermont, Burlington, VT, USA; Division of Cardiovascular Sciences, University of Manchester, Manchester, UK. Electronic address:

The just-in time delivery of oxygen and nutrients to active brain regions to support function (functional hyperemia; FH) is mediated by not yet fully understood mechanisms collectively referred to as 'neurovascular coupling' (NVC). In a recent publication (eLife 2021) Thakore et al. provide profound mechanistic insight how the capillary endothelial transient receptor potential ankyrin 1 (TRPA1) channel contribute to blood flow control and functional hyperemia in the brain. Read More

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Chromatin-embedded reporter genes: Quantification of stimulus-induced gene transcription.

Gene 2021 Apr 10:145645. Epub 2021 Apr 10.

Department of Medical Biochemistry and Molecular Biology, Saarland University Medical Faculty, D-66421 Homburg, Germany.

Receptors and ion channels expressed on the cell surface ensure proper communication between the cells and the environment. In multicellular organism, stimulus-regulated gene transcription is the basis for the communication with the environment allowing individual cells to respond to stimuli such as nutrients, chemical stressors and signaling molecules released by other cells of the organism. Hormones, cytokines, and mitogens bind to receptors and ion channels and induce intracellular signaling cascades involving second messengers, kinases, phosphatases, and changes in the concentration of particular ions. Read More

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Different Roles of Subcortical Inputs in V1 Responses to Luminance and Contrast.

Eur J Neurosci 2021 Apr 13. Epub 2021 Apr 13.

State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.

Cells in the primary visual cortex (V1) generally respond weakly to large uniform luminance stimuli. Only a subset of V1 cells is thought to encode uniform luminance information. In natural scenes, local luminance is an important feature for defining an object that varies and coexists with local spatial contrast. Read More

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Degradation of Polyamide Nanofiltration Membranes by Bromine: Changes of Physiochemical Properties and Filtration Performance.

Environ Sci Technol 2021 Apr 13. Epub 2021 Apr 13.

Department of Civil Engineering, University of Hong Kong, Pokfulam, Hong Kong.

The potential coexistence and interaction of bromine and polyamide membranes during membrane-based water treatment prompts us to investigate the effect of bromine on membrane performance. For fully aromatic polyamide membrane NF90 exposed under a mild bromination condition (10 mg/L), bromine incorporation resulted in more negatively charged (-13 vs -25 mV) and hydrophobic (55.2 vs 58. Read More

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