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https://www.readbyqxmd.com/read/29149059/a-high-performance-portable-transient-electro-magnetic-sensor-for-unexploded-ordnance-detection
#1
Haofeng Wang, Shudong Chen, Shuang Zhang, Zhiwen Yuan, Haiyang Zhang, Dong Fang, Jun Zhu
Portable transient electromagnetic (TEM) systems can be well adapted to various terrains, including mountainous, woodland, and other complex terrains. They are widely used for the detection of unexploded ordnance (UXO). As the core component of the portable TEM system, the sensor is constructed with a transmitting coil and a receiving coil. Based on the primary field of the transmitting coil and internal noise of the receiving coil, the design and testing of such a sensor is described in detail. Results indicate that the primary field of the transmitting coil depends on the diameter, mass, and power of the coil...
November 17, 2017: Sensors
https://www.readbyqxmd.com/read/29146456/is-more-always-better-how-different-doses-of-exercise-after-incomplete-spinal-cord-injury-affects-the-membrane-properties-of-deep-dorsal-horn-interneurons
#2
M M Rank, M P Galea, R Callister, R J Callister
Interneurons in the deep dorsal horn (DDH) of the spinal cord process somatosensory input, and form an important link between upper and lower motoneurons to subsequently shape motor output. Exercise training after SCI is known to improve functional motor recovery, but little is known about the mechanisms within spinal cord neurons that underlie these improvements. Here we investigate how the properties of DDH interneurons are affected by spinal cord injury (SCI) alone, and SCI in combination with different 'doses' of treadmill exercise training (3, 6, and 9wks)...
November 13, 2017: Experimental Neurology
https://www.readbyqxmd.com/read/29143930/photovoltaic-cell-electrical-heating-system-for-removing-snow-on-panel-including-verification
#3
Agnes Weiss, Helmut Weiss
Small photovoltaic plants in private ownership are typically rated at 5 kW (peak). The panels are mounted on roofs at a decline angle of 20° to 45°. In winter time, a dense layer of snow at a width of e.g., 10 cm keeps off solar radiation from the photovoltaic cells for weeks under continental climate conditions. Practically, no energy is produced over the time of snow coverage. Only until outside air temperature has risen high enough for a rather long-time interval to allow partial melting of snow; the snow layer rushes down in an avalanche...
November 16, 2017: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/29141003/trpa1-and-trpv1-are-required-for-lidocaine-evoked-calcium-influx-and-neuropeptide-release-but-not-cytotoxicity-in-mouse-sensory-neurons
#4
Mirjam Eberhardt, Thomas Stueber, Jeanne de la Roche, Christine Herzog, Andreas Leffler, Peter W Reeh, Katrin Kistner
BACKGROUND: Local anaesthetics (LA) reduce neuronal excitability by inhibiting voltage-gated Na+ channels. When applied at high concentrations in the direct vicinity of nerves, LAs can also induce relevant irritation and neurotoxicity via mechanisms involving an increase of intracellular Ca2+. In the present study we explored the role of the Ca2+-permeable ion channels TRPA1 and TRPV1 for lidocaine-induced Ca2+-influx, neuropeptide release and neurotoxicity in mouse sensory neurons. METHODS: Cultured dorsal root ganglion (DRG) neurons from wildtype and mutant mice lacking TRPV1, TRPA1 or both channels were explored by means of calcium imaging, whole-cell patch clamp recordings and trypan blue staining for cell death...
2017: PloS One
https://www.readbyqxmd.com/read/29138759/identification-of-persistent-and-resurgent-sodium-currents-in-spiral-ganglion-neurons-cultured-from-the-mouse-cochlea
#5
Lorcan Browne, Katie E Smith, Daniel J Jagger
In spiral ganglion neurons (SGNs), the afferent single units of the auditory nerve, high spontaneous and evoked firing rates ensure preservation of the temporal code describing the key features of incoming sound. During postnatal development, the spatiotemporal distribution of ion channel subtypes contributes to the maturation of action potential generation in SGNs, and to their ability to generate spike patterns that follow rapidly changing inputs. Here we describe tetrodotoxin (TTX)-sensitive Na(+) currents in SGNs cultured from mice, whose properties may support this fast spiking behavior...
November 2017: ENeuro
https://www.readbyqxmd.com/read/29134638/inhibition-of-acid-sensing-ion-channels-by-diminazene-and-apetx2-evoke-partial-and-highly-variable-antihyperalgesia-in-a-rat-model-of-inflammatory-pain
#6
Jia Yu Peppermint Lee, Natalie J Saez, Ben Cristofori-Armstrong, Raveendra Anangi, Glenn F King, Maree T Smith, Lachlan D Rash
BACKGROUND AND PURPOSE: Acid-sensing ion channels (ASICs) are primary acid sensors in mammals, with the ASIC1b and ASIC3 subtypes being involved in peripheral nociception. The antiprotozoal drug diminazene is a moderately potent ASIC inhibitor but its analgesic activity has not been assessed. EXPERIMENTAL APPROACH: We determined the ASIC subtype selectivity of diminazene and the mechanism by which it inhibits ASICs using voltage-clamp electrophysiology of Xenopus oocytes expressing ASICs 1-3...
November 14, 2017: British Journal of Pharmacology
https://www.readbyqxmd.com/read/29134326/inhibition-of-the-voltage-dependent-k-current-by-the-tricyclic-antidepressant-desipramine-in-rabbit-coronary-arterial-smooth-muscle-cells
#7
Sung Eun Shin, Hongliang Li, Jin Ryeol An, Mi Seon Seo, Sung Hun Na, Won-Kyo Jung, Amy L Firth, Kwon-Soo Ha, Eun-Taek Han, Seok-Ho Hong, Il-Whan Choi, Won Sun Park
We describe the effect of a tricyclic antidepressant drug desipramine on voltage-dependent K(+) (Kv) currents in freshly isolated rabbit coronary arterial smooth muscle cells using a conventional whole-cell patch clamp technique. Application of desipramine rapidly decreased the Kv current amplitude in a concentration-dependent manner, with an IC50 value of 5.91 ± 0.18 μM and a Hill coefficient of 0.61 ± 0.09. The steady-state inactivation curves of the Kv channels were not affected by desipramine. However, desipramine shifted the steady-state inactivation curves toward a more negative potential...
November 13, 2017: Cardiovascular Toxicology
https://www.readbyqxmd.com/read/29133173/effects-of-norquetiapine-the-active-metabolite-of-quetiapine-on-cloned-herg-potassium-channels
#8
Hong Joon Lee, Jin-Sung Choi, Bok Hee Choi, Sang June Hahn
Quetiapine is an atypical antipsychotic drug that is widely used for the treatment of schizophrenia. It is mainly metabolized by a cytochrome P450 system in the liver. Norquetiapine is a major active metabolite in humans with a pharmacological profile that differs distinctly from that of quetiapine. We used the whole-cell patch-clamp technique to investigate the effects of norquetiapine on hERG channels that are stably expressed in HEK cells. Quetiapine and norquetiapine inhibited the hERG tail currents at -50mV in a concentration-dependent manner with IC50 values of 8...
November 11, 2017: Neuroscience Letters
https://www.readbyqxmd.com/read/29131061/kinetic-aspects-of-verapamil-binding-on-rate-on-wild-type-and-six-hkv1-3-mutant-channels
#9
Ann-Kathrin Diesch, Stephan Grissmer
BACKGROUND/AIMS: The human-voltage gated Kv1.3 channel (hKv1.3) is expressed in T- and B lymphocytes. Verapamil is able to block hKv1.3 channels. We characterized the effect of verapamil on currents through hKv1.3 channels paying special attention to the on-rate (kon) of verapamil. By comparing on-rates obtained in wild-type (wt) and mutant channels a binding pocket for verapamil and impacts of different amino acid residues should be investigated. METHODS: Using the whole-cell patch clamp technique the action of verapamil on currents through wild-type and six hKv1...
November 6, 2017: Cellular Physiology and Biochemistry
https://www.readbyqxmd.com/read/29130489/angiotensin-1-7-modulates-electrophysiological-characteristics-and-calcium-homeostasis-in-pulmonary-veins-cardiomyocytes-via-mas-pi3k-enos-signaling-pathway
#10
Yen-Yu Lu, Wen-Shiann Wu, Yung-Kuo Lin, Chen-Chuan Cheng, Yao-Chang Chen, Shih-Ann Chen, Yi-Jen Chen
BACKGROUND: Atrial fibrillation (AF) is the most common sustained arrhythmia, and pulmonary veins (PVs) play a critical role in triggering AF. Angiotensin (Ang)-(1-7) regulates calcium (Ca(2+) ) homeostasis and also plays a critical role in cardiovascular pathophysiology. However, the role of Ang-(1-7) in PV arrhythmogenesis remains unclear. MATERIALS AND METHODS: Conventional microelectrodes, whole-cell patch-clamp, and the Fluo-3 fluorimetric ratio technique were used to record ionic currents and intracellular Ca(2+) in isolated rabbit PV preparations, and in single isolated PV cardiomyocytes, before and after administration of Ang-(1-7)...
November 12, 2017: European Journal of Clinical Investigation
https://www.readbyqxmd.com/read/29128793/phytochemicals-genistein-and-capsaicin-modulate-kv2-1-channel-gating
#11
Iván A Aréchiga-Figueroa, Rita Morán-Zendejas, Mayra Delgado-Ramírez, Aldo A Rodríguez-Menchaca
BACKGROUND: Phytochemicals are a large group of plant-derived compounds that have a broad range of pharmacological effects. Some of these effects are derived from their action on transport proteins, including ion channels. The present study investigates the effects of the phytochemicals genistein and capsaicin on voltage-gated potassium Kv2.1 channels. METHODS: The whole-cell patch clamp technique was used to explore the regulation of Kv2.1 channels expressed in HEK293 cells by genistein and capsaicin...
June 3, 2017: Pharmacological Reports: PR
https://www.readbyqxmd.com/read/29128504/biophysical-comparison-of-sodium-currents-in-native-cardiac-myocytes-and-human-induced-pluripotent-stem-cell-derived-cardiomyocytes
#12
Robert J Goodrow, Suveer Desai, Jacqueline A Treat, Brian K Panama, Mayurika Desai, Vladislav V Nesterenko, Jonathan M Cordeiro
INTRODUCTION: Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) are used for safety pharmacology and to investigate genetic diseases affecting cardiac ion channels. It is unclear whether adult myocytes or hiPSC-CMs are the better platform for cardiac safety pharmacology. We examined the biophysical and molecular properties of INa in adult myocytes and hiPSC-CMs. METHODS: hiPSC-CMs were plated at low density. Atrial and ventricular cells were obtained from dog hearts...
November 8, 2017: Journal of Pharmacological and Toxicological Methods
https://www.readbyqxmd.com/read/29127702/towards-functional-selectivity-for-%C3%AE-6%C3%A2-3%C3%AE-2-gabaa-receptors-a-series-of-novel-pyrazoloquinolinones
#13
Marco Treven, David C B Siebert, Raphael Holzinger, Konstantina Bampali, Jure Fabjan, Zdravko Varagic, Laurin Wimmer, Friederike Steudle, Petra Scholze, Michael Schnürch, Marko D Mihovilovic, Margot Ernst
BACKGROUND AND PURPOSE: The γ - aminobutyric acid type A (GABAA ) receptors are ligand-gated ion channels which play an important role in neurotransmission. Their variety of binding sites serves as an appealing target for many clinically relevant drugs. Here, we explored the functional selectivity of modulatory effects at specific extracellular α+/®- interfaces, using a systematically varied series of pyrazoloquinolinones. EXPERIMENTAL APPROACH: Recombinant GABAA receptors were expressed in Xenopus laevis oocytes and modulatory effects on GABA elicited currents by the newly synthesized and the reference compounds were investigated by the two-electrode voltage clamp method...
November 11, 2017: British Journal of Pharmacology
https://www.readbyqxmd.com/read/29117522/the-fast-component-of-herg-gating-charge-an-interaction-between-d411-in-the-s1-and-s4-residues
#14
Ying Dou, Logan C Macdonald, Yue Wu, David Fedida
Kv11.1 (hERG) is a voltage-gated potassium channel that shows very slow ionic current activation kinetics, and an unusual underlying biphasic gating charge movement with fast and slow components that differ greatly in time course. The structural basis and role of the fast component of gating charge (Qfast) is unclear, and its relationship to the slow activation of hERG channels is not understood. In this study we have used the cut-open oocyte voltage-clamp technique to investigate the relationship of fast gating charge movement-to-residue interactions between D411 at the bottom of the S1, and lower S4 domain charged and uncharged residues...
November 7, 2017: Biophysical Journal
https://www.readbyqxmd.com/read/29108650/biophysical-characterization-of-genetically-encoded-voltage-sensor-asap1-dynamic-range-improvement
#15
Elizabeth E L Lee, Francisco Bezanilla
Recent work has introduced a new fluorescent voltage sensor, ASAP1, which can monitor rapid trains of action potentials in cultured neurons. This indicator is based on the Gallus gallus voltage-sensitive phosphatase with the phosphatase domain removed and a circularly permuted GFP placed in the S3-S4 linker. However, many of the biophysical details of this indicator remain unknown. In this work, we study the biophysical properties of ASAP1. Using the cut-open voltage clamp technique, we have simultaneously recorded fluorescence signals and gating currents from Xenopus laevis oocytes expressing ASAP1...
November 3, 2017: Biophysical Journal
https://www.readbyqxmd.com/read/29107231/influence-of-the-rdl-a301s-mutation-in-the-brown-planthopper-nilaparvata-lugens-on-the-activity-of-phenylpyrazole-insecticides
#16
William T Garrood, Christoph T Zimmer, Oliver Gutbrod, Bettina Lüke, Martin S Williamson, Chris Bass, Ralf Nauen, T G Emyr Davies
We discovered the A301S mutation in the RDL GABA-gated chloride channel of fiprole resistant rice brown planthopper, Nilaparvata lugens populations by DNA sequencing and SNP calling via RNASeq. Ethiprole selection of two field N. lugens populations resulted in strong resistance to both ethiprole and fipronil and resulted in fixation of the A301S mutation, as well as the emergence of another mutation, Q359E in one of the selected strains. To analyse the roles of these mutations in resistance to phenylpyrazoles, three Rdl constructs: wild type, A301S and A301S+Q359E were expressed in Xenopus laevis oocytes and assessed for their sensitivity to ethiprole and fipronil using two-electrode voltage-clamp electrophysiology...
October 2017: Pesticide Biochemistry and Physiology
https://www.readbyqxmd.com/read/29106970/functional-studies-reveal-the-similarities-and-differences-between-am2-and-bm2-proton-channels-from-influenza-viruses
#17
Chunlong Ma, Jun Wang
AM2 and BM2 proton channels are attractive antiviral drug targets due to their essential roles during influenza virus replication. Although both AM2 and BM2 are proton-selective ion channels, they share little sequence similarity except for the HXXXW sequence, which suggests that their proton conductance properties might differ. To test this hypothesis, we applied two-electrode voltage clamp electrophysiological assays to study the specific conductance, leakage current, channel activation, and inhibition of AM2 and BM2 proton channels...
October 26, 2017: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/29105388/in-vitro-differentiation-of-neural-like-cells-from-human-embryonic-stem-cells-by-a-combination-of-dorsomorphin-xav939-and-a8301
#18
Zahra Valizadeh-Arshad, Ebrahim Shahbazi, Shiva Hashemizadeh, Azadeh Moradmand, Meyssam Jangkhah, Sahar Kiani
OBJECTIVES: Motor neuron differentiation from human embryonic stem cells (hESCs) is a goal of regenerative medicine to provide cell therapy as treatments for diseases that damage motor neurons. Most protocols lack adequate efficiency in generating functional motor neurons. However, small molecules present a new approach to overcome this challenge. The aim of this research is to replace morphogen factors with a cocktail of efficient, affordable small molecules for effective, low cost motor neuron differentiation...
January 2018: Cell Journal
https://www.readbyqxmd.com/read/29104047/mechanism-of-sodium-hydrosulfide-modulation-of-l-type-calcium-channels-in-rat-colonic-smooth-muscle-cells
#19
Qincai Tang, Xiaojing Quan, Lin Yan, Haixia Ren, Wei Chen, Hong Xia, Hesheng Luo
Hydrogen sulfide (H2S) can exert different effects on the gastrointestinal tract by modulating ion channels. Previously, we found that H2S donor sodium hydrosulfide (NaHS) regulates colonic motility through L-type calcium channels, but the molecular mechanism remains unknown. The present study was designed to investigate possible mechanisms underlying the modulation of L-type calcium channels by NaHS in rat colonic smooth muscle cells. L-type calcium currents in colonic smooth muscle cells were recorded using the whole-cell patch-clamp technique...
November 9, 2017: European Journal of Pharmacology
https://www.readbyqxmd.com/read/29097440/desensitization-and-tolerance-of-mu-opioid-receptors-on-pontine-kolliker-fuse-neurons
#20
Erica S Levitt, John T Williams
Acute desensitization of mu opioid receptors is thought to be an initial step in the development of tolerance to opioids. Given the resistance of the respiratory system to develop tolerance, desensitization of neurons in the Kölliker-Fuse (KF), a key area in the respiratory circuit, was examined. The activation of G protein-coupled inwardly rectifying potassium (GIRK) current was measured using whole-cell voltage-clamp recordings from KF and locus coeruleus (LC) neurons contained in acute rat brain slices...
November 2, 2017: Molecular Pharmacology
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