keyword
MENU ▼
Read by QxMD icon Read
search

Voltage Mapping

keyword
https://www.readbyqxmd.com/read/28211132/comparison-of-left-atrial-voltage-between-sinus-rhythm-and-atrial-fibrillation-in-association-with-electrogram-wave-form
#1
Masaharu Masuda, Masashi Fujita, Osamu Iida, Shin Okamoto, Takayuki Ishihara, Kiyonori Nanto, Takashi Kanda, Akihiro Sunaga, Takuya Tsujimura, Yasuhiro Matsuda, Takuya Ohashi, Masaaki Uematsu
BACKGROUND: The efficacy of low-voltage-guided ablation in addition to pulmonary vein (PV) isolation for atrial fibrillation (AF) has been reported with voltage mapping being performed during sinus rhythm (SR) or AF. The study aimed to compare the left atrial voltage between SR and AF in association with the electrogram wave form. METHODS: This prospective observational study included 30 consecutive patients with persistent AF. After completion of PV isolation, electrogram points were taken during both SR and AF at the identical locations evenly throughout the left atrium...
February 16, 2017: Pacing and Clinical Electrophysiology: PACE
https://www.readbyqxmd.com/read/28202723/mapping-of-voltage-sensor-positions-in-resting-and-inactivated-mammalian-sodium-channels-by-lret
#2
Tomoya Kubota, Thomas Durek, Bobo Dang, Rocio K Finol-Urdaneta, David J Craik, Stephen B H Kent, Robert J French, Francisco Bezanilla, Ana M Correa
Voltage-gated sodium channels (Navs) play crucial roles in excitable cells. Although vertebrate Nav function has been extensively studied, the detailed structural basis for voltage-dependent gating mechanisms remain obscure. We have assessed the structural changes of the Nav voltage sensor domain using lanthanide-based resonance energy transfer (LRET) between the rat skeletal muscle voltage-gated sodium channel (Nav1.4) and fluorescently labeled Nav1.4-targeting toxins. We generated donor constructs with genetically encoded lanthanide-binding tags (LBTs) inserted at the extracellular end of the S4 segment of each domain (with a single LBT per construct)...
February 15, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28199072/genetic-risk-score-analysis-in-early-onset-bipolar-disorder
#3
Paul E Croarkin, Joan L Luby, Kelly Cercy, Jennifer R Geske, Marin Veldic, Matthew Simonson, Paramjit T Joshi, Karen Dineen Wagner, John T Walkup, Malik M Nassan, Alfredo B Cuellar-Barboza, Leah Casuto, Susan L McElroy, Peter S Jensen, Mark A Frye, Joanna M Biernacka
OBJECTIVE: In this study, we performed a candidate genetic risk score (GRS) analysis of early-onset bipolar disorder (BD). METHODS: Treatment of Early Age Mania (TEAM) study enrollment and sample collection took place from 2003 to 2008. Mayo Clinic Bipolar Biobank samples were collected from 2009 to 2013. Genotyping and analyses for the present study took place from 2013 to 2014. The diagnosis of BD was based on Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision criteria...
February 14, 2017: Journal of Clinical Psychiatry
https://www.readbyqxmd.com/read/28193560/electron-beam-induced-current-and-active-secondary-electron-voltage-contrast-with-aberration-corrected-electron-probes
#4
Myung-Geun Han, Joseph A Garlow, Matthew S J Marshall, Amanda L Tiano, Stanislaus S Wong, Sang-Wook Cheong, Frederick J Walker, Charles H Ahn, Yimei Zhu
The ability to map out electrostatic potentials in materials is critical for the development and the design of nanoscale electronic and spintronic devices in modern industry. Electron holography has been an important tool for revealing electric and magnetic field distributions in microelectronics and magnetic-based memory devices, however, its utility is hindered by several practical constraints, such as charging artifacts and limitations in sensitivity and in field of view. In this article, we report electron-beam-induced-current (EBIC) and secondary-electron voltage-contrast (SE-VC) with an aberration-corrected electron probe in a transmission electron microscope (TEM), as complementary techniques to electron holography, to measure electric fields and surface potentials, respectively...
February 6, 2017: Ultramicroscopy
https://www.readbyqxmd.com/read/28178296/identification-of-a-vacuolar-proton-channel-that-triggers-the-bioluminescent-flash-in-dinoflagellates
#5
Juan D Rodriguez, Saddef Haq, Tsvetan Bachvaroff, Kristine F Nowak, Scott J Nowak, Deri Morgan, Vladimir V Cherny, Maredith M Sapp, Steven Bernstein, Andrew Bolt, Thomas E DeCoursey, Allen R Place, Susan M E Smith
In 1972, J. Woodland Hastings and colleagues predicted the existence of a proton selective channel (HV1) that opens in response to depolarizing voltage across the vacuole membrane of bioluminescent dinoflagellates and conducts protons into specialized luminescence compartments (scintillons), thereby causing a pH drop that triggers light emission. HV1 channels were subsequently identified and demonstrated to have important functions in a multitude of eukaryotic cells. Here we report a predicted protein from Lingulodinium polyedrum that displays hallmark properties of bona fide HV1, including time-dependent opening with depolarization, perfect proton selectivity, and characteristic ΔpH dependent gating...
2017: PloS One
https://www.readbyqxmd.com/read/28161890/homology-guided-mutational-analysis-reveals-the-functional-requirements-for-antinociceptive-specificity-of-crmp2-derived-peptides
#6
Aubin Moutal, Wennan Li, Yue Wang, Weina Ju, Shizhen Luo, Song Cai, Liberty François-Moutal, Samantha Perez-Miller, Jackie Hu, Erik T Dustrude, Todd W Vanderah, Vijay Gokhale, May Khanna, Rajesh Khanna
BACKGROUND AND PURPOSE: N-type voltage-gated calcium (CaV2.2) channels are critical determinants of increased neuronal excitability and neurotransmission accompanying persistent neuropathic pain. Despite CaV2.2 antagonism being recommended as first-line treatment for neuropathic pain, calcium-current blocking gabapentinoids inadequately alleviate chronic pain symptoms and are often mired by numerous side-effects. Collapsin response mediator protein 2 (CRMP2) targets CaV2.2 to the sensory neuron membrane, and allosterically modulates Cav2...
February 5, 2017: British Journal of Pharmacology
https://www.readbyqxmd.com/read/28159537/diethyl-4-4-dihydroxy-8-3-neolign-7-7-dien-9-9-dionate-exhibits-antihypertensive-activity-in-rats-through-increase-in-intracellular-cgmp-level-and-blockade-of-calcium-channels
#7
Arjun Singh, B Sathish Kumar, Sarfaraz Alam, Hina Iqbal, Mohammad Shafiq, Feroz Khan, Arvind S Negi, Kashif Hanif, Debabrata Chanda
We report here the antihypertensive and vasorelaxant potential of some steroidal and non-steroidal compounds identified through a library of compounds. All the novel analogues showed vasorelaxant potential in isolated rat aorta. The most potent lead neolignan1 (Diethyl-4,4'-dihydroxy-8,3'-neolign-7,7'-dien-9,9'-dionate) produced concentration dependent relaxation with [pD2 5.16 ± 0.05; n=16 and Emax 96.97% ± 1.12%; n=16]. The neolignan1 relaxation is independent of endothelium and is sensitive to ODQ (1H-[1, 2, 4] oxadiazolo [4, 3-a] quinoxalin-1-one; a blocker of soluble guanylyl cyclase (sGC) which synthesizes cGMP (cyclic guanosine monophosphate))...
January 31, 2017: European Journal of Pharmacology
https://www.readbyqxmd.com/read/28150151/structure-based-assessment-of-disease-related-mutations-in-human-voltage-gated-sodium-channels
#8
REVIEW
Weiyun Huang, Minhao Liu, S Frank Yan, Nieng Yan
Voltage-gated sodium (Nav) channels are essential for the rapid upstroke of action potentials and the propagation of electrical signals in nerves and muscles. Defects of Nav channels are associated with a variety of channelopathies. More than 1000 disease-related mutations have been identified in Nav channels, with Nav1.1 and Nav1.5 each harboring more than 400 mutations. Nav channels represent major targets for a wide array of neurotoxins and drugs. Atomic structures of Nav channels are required to understand their function and disease mechanisms...
February 1, 2017: Protein & Cell
https://www.readbyqxmd.com/read/28135063/interface-electrical-properties-of-al2o3-thin-films-on-graphene-obtained-by-atomic-layer-deposition-with-in-situ-seed-like-layer
#9
Gabriele Fisichella, Emanuela Schilirò, Salvatore Di Franco, Patrick Fiorenza, Raffaella Lo Nigro, Fabrizio Roccaforte, Sebastiano Ravesi, Filippo Giannazzo
High quality thin insulating films on graphene (Gr) are essential for field effect transistors (FETs) and other electronics applications of this material. Atomic Layer Deposition (ALD) is the method of choice to deposit high-κ dielectrics with excellent thickness uniformity and conformal coverage. However, to start the growth on the sp(2) Gr surface a chemical pre-functionalization or the physical deposition of a seed layer are required, which can effect, to some extent, the electrical properties of Gr. In this paper we report a detailed morphological, structural and electrical investigation of Al2O3 thin films grown by a two-steps ALD process on large area Gr membranes residing on an Al2O3/Si substrate...
January 30, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28120237/hibernating-substrate-of-ventricular-tachycardia-a-three-dimensional-metabolic-and-electro-anatomic-assessment
#10
Ayman A Hussein, Michelle Niekoop, Vasken Dilsizian, Yousra Ghzally, Mohammed Abdulghani, Ramazan Asoglu, Wengen Chen, Mark Smith, Vincent See, Stephen R Shorofsky, Timm-Michael Dickfeld
PURPOSE: Hibernating myocardium (HM) is associated with sudden cardiac death (SCD). Little is known about the electrophysiological properties of HM and the basis of its association with SCD. We aimed to electrophysiologically characterize HM in patients with ventricular tachycardia (VT). METHODS: Endocardial voltage mapping, metabolic (18)FDG-positron emission tomography (PET) and perfusion (82)Rb, (201)Tl, or (99m)Tc scans were performed in 61 ischemic heart disease patients with VT...
January 25, 2017: Journal of Interventional Cardiac Electrophysiology: An International Journal of Arrhythmias and Pacing
https://www.readbyqxmd.com/read/28119399/an-als-associated-mutant-sod1-rapidly-suppresses-kcnt1-slack-na-activated-k-channels-in-aplysia-neurons
#11
Yalan Zhang, Weiming Ni, Arthur L Horwich, Leonard K Kaczmarek
: Mutations that alter levels of Slack (KCNT1) Na(+)-activated K(+) current produce devastating effects on neuronal development and neuronal function. We now find that Slack currents are rapidly suppressed by oligomers of mutant human Cu/Zn superoxide dismutase 1 (SOD1), which are associated with motor neuron toxicity in an inherited form of amyotrophic lateral sclerosis (ALS). We recorded from bag cell neurons of Aplysia Californica, a model system to study neuronal excitability. We found that injection of fluorescent wild-type SOD1 (wt SOD1YFP) or monomeric mutant G85R SOD1YFP had no effect on net ionic currents measured under voltage clamp...
January 24, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/28113215/modeling-endovascular-mri-coil-coupling-with-transmit-rf-excitation
#12
Madhav Venkateswaran, Orhan Unal, Samuel Hurley, Alexey Samsonov, Peng Wang, Sean Fain, Krishna Kurpad
OBJECTIVE: To model inductive coupling of endovascular coils with transmit RF excitation for selecting coils for MRI-guided interventions. METHODS: Independent and computationally efficient FEM models are developed for the endovascular coil, cable, transmit excitation and imaging domain. Electromagnetic and circuit solvers are coupled to simulate net B1+ fields and induced currents and voltages. Our models are validated using the Bloch Siegert B1+ mapping sequence for a series-tuned multimode coil, capable of tracking, wireless visualization and high resolution endovascular imaging...
March 4, 2016: IEEE Transactions on Bio-medical Engineering
https://www.readbyqxmd.com/read/28107626/polymeric-nanofibers-with-ultrahigh-piezoelectricity-via-self-orientation-of-nanocrystals
#13
Xia Liu, Jing Ma, Xiaoming Wu, Liwei Lin, Xiaohong Wang
Piezoelectricity in macromolecule polymers has been gaining immense attention, particularly for applications in biocompatible, implantable, and flexible electronic devices. This paper introduces core-shell-structured piezoelectric polyvinylidene fluoride (PVDF) nanofibers chemically wrapped by graphene oxide (GO) lamellae (PVDF/GO nanofibers), in which the polar β-phase nanocrystals are formed and uniaxially self-oriented by the synergistic effect of mechanical stretching, high-voltage alignment, and chemical interactions...
January 20, 2017: ACS Nano
https://www.readbyqxmd.com/read/28095830/kv7-voltage-activated-potassium-channel-inhibitors-reduce-fluid-resuscitation-requirements-after-hemorrhagic-shock-in-rats
#14
Sean P Nassoiy, Kenneth L Byron, Matthias Majetschak
BACKGROUND: Recent evidence suggests that drugs targeting Kv7 channels could be used to modulate vascular function and blood pressure. Here, we studied whether Kv7 channel inhibitors can be utilized to stabilize hemodynamics and reduce resuscitation fluid requirements after hemorrhagic shock. METHODS: Anesthetized male Sprague-Dawley rats were instrumented with arterial and venous catheters for blood pressure monitoring, hemorrhage and fluid resuscitation. Series 1: Linopirdine (Kv7 channel blocker, 0...
January 17, 2017: Journal of Biomedical Science
https://www.readbyqxmd.com/read/28095774/multiple-focal-and-macroreentrant-left-atrial-tachycardias-originating-from-a-spontaneous-scar-at-the-contiguous-aorta-left-atrium-area-in-a-patient-with-hypertrophic-cardiomyopathy-a-case-report
#15
Kyoichiro Yazaki, Yoichi Ajiro, Fumiaki Mori, Masahiro Watanabe, Kei Tsukamoto, Takashi Saito, Keiko Mizobuchi, Kazunori Iwade
BACKGROUND: Spontaneous scar-related left atrial tachycardia (AT) is a rare arrhythmia. We describe a patient with hypertrophic cardiomyopathy (HCM) who developed multiple, both focal and macroreentrant left ATs associated with a spontaneous scar located at the aorta-left atrium (LA) contiguous area. CASE PRESENTATION: A 65-year-old man with HCM complained of palpitations. Twelve-lead electrocardiogram showed narrow QRS tachycardia with 2:1 atrioventricular conduction...
January 17, 2017: BMC Cardiovascular Disorders
https://www.readbyqxmd.com/read/28090710/fibrillatory-wave-amplitude-on-transesophageal-ecg-as-a-marker-of-left-atrial-low-voltage-areas-in-patients-with-persistent-atrial-fibrillation
#16
Ran Yin, Yongnan Fu, Zhongming Yang, Bingong Li, Jintian Pen, Zeqi Zheng
BACKGROUND: Low-voltage areas (LVAs) are frequently observed in patients with persistent atrial fibrillation (PeAF) and may represent adverse atrial remodeling. However, noninvasive method of evaluating LAVs is not well established. METHODS: In a cohort of 68 patients with PeAF, endocardial voltage maps of left atrium (LA) were created during sinus rhythm after pulmonary vein isolation (PVI). LVAs were defined as areas with electrogram amplitudes <0.5 mV. LA-LVAs were correlated with clinical, echocardiographic, surface, and transesophageal electrocardiography (TE-ECG) variables...
January 16, 2017: Annals of Noninvasive Electrocardiology
https://www.readbyqxmd.com/read/28089743/multichannel-visual-evoked-potentials-in-the-assessment-of-visual-pathways-in-children-with-marked-brain-abnormalities
#17
Sian E Handley, Alki C Liasis
PURPOSE: To demonstrate how multichannel visual evoked potentials (VEPs) can provide quantitative measures of visual function in in children with marked cortical anatomy abnormalities. METHODS: Four children with marked brain pathology (2 holoprosencephaly, 2 giant interhemispheric cysts with hydrocephalus) underwent pattern reversal and flash VEP recordings from 16 equally distributed electrodes. Voltage maps of the major VEP components were constructed, and their distributions were compared to the magnetic resonance imaging (MRI) findings...
January 9, 2017: Journal of AAPOS: the Official Publication of the American Association for Pediatric Ophthalmology and Strabismus
https://www.readbyqxmd.com/read/28078312/biallelic-scn10a-mutations-in-neuromuscular-disease-and-epileptic-encephalopathy
#18
Marios Kambouris, Julien Thevenon, Ariane Soldatos, Allison Cox, Joshi Stephen, Tawfeg Ben-Omran, Yasser Al-Sarraj, Hala Boulos, William Bone, James C Mullikin, Alice Masurel-Paulet, Judith St-Onge, Yannis Dufford, Corrine Chantegret, Christel Thauvin-Robinet, Jamil Al-Alami, Laurence Faivre, Jean Baptiste Riviere, William A Gahl, Alexander G Bassuk, May Christine V Malicdan, Hatem El-Shanti
OBJECTIVES: Two consanguineous families, one of Sudanese ethnicity presenting progressive neuromuscular disease, severe cognitive impairment, muscle weakness, upper motor neuron lesion, anhydrosis, facial dysmorphism, and recurrent seizures and the other of Egyptian ethnicity presenting with neonatal hypotonia, bradycardia, and recurrent seizures, were evaluated for the causative gene mutation. METHODS AND RESULTS: Homozygosity mapping and whole exome sequencing (WES) identified damaging homozygous variants in SCN10A, namely c...
January 2017: Annals of Clinical and Translational Neurology
https://www.readbyqxmd.com/read/28065832/a-novel-method-to-enhance-phenotype-epicardial-functional-substrates-and-ventricular-tachyarrhythmias-in-brugada-syndrome
#19
Fa-Po Chung, Sunu Budhi Raharjo, Yenn-Jiang Lin, Shih-Lin Chang, Li-Wei Lo, Yu-Feng Hu, Ta-Chuan Tuan, Tze-Fan Chao, Jo-Nan Liao, Chin-Yu Lin, Yao-Ting Chang, Yuan Hung, Abigail Te, Shinya Yamada, Hiroshi Tasaka, Shih-Ann Chen, Chin-Tien Wang
BACKGROUND: Fever is associated with the manifestation of Brugada phenotype and ventricular tachycardia/ventricular fibrillation (VT/VF) in patients with Brugada syndrome (BrS). The thermal effect on the pathogenesis of functional substrates in BrS remains unknown. OBJECTIVE: This study aimed to elucidate the thermal effect on BrS phenotype, VT/VF, and electrophysiological characteristics of epicardial functional substrates in BrS. METHODS: We consecutively studied 15 patients with BrS receiving radiofrequency catheter ablation for drug-refractory ventricular tachyarrhythmias...
January 6, 2017: Heart Rhythm: the Official Journal of the Heart Rhythm Society
https://www.readbyqxmd.com/read/28026917/voltage-combined-with-pace-mapping-is-simple-and-effective-for-ablation-of-noninducible-premature-ventricular-contractions-originating-from-the-right-ventricular-outflow-tract
#20
Zefeng Wang, Heping Zhang, Hui Peng, Xuhua Shen, Zhijun Sun, Can Zhao, Ruiqing Dong, Huikuan Gao, Yongquan Wu
BACKGROUND: Premature ventricular contractions (PVCs) from the right ventricular outflow tract (RVOT) can resist conventional mapping strategies. Studies regarding optimal mapping and ablation methods for patients with noninducible RVOT-PVCs are limited. We retrospectively evaluated the efficacy and safety of a novel mapping strategy for these cases: voltage mapping combined with pace mapping. HYPOTHESIS: METHODS: We retrospectively included symptomatic patients (n = 148; 76 males; age, 44...
December 2016: Clinical Cardiology
keyword
keyword
36641
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"