keyword
MENU ▼
Read by QxMD icon Read
search

Rotor

keyword
https://www.readbyqxmd.com/read/28327621/neutron-scattering-observation-of-quasi-free-rotations-of-water-confined-in-carbon-nanotubes
#1
G Briganti, G Rogati, A Parmentier, M Maccarini, F De Luca
The translational and orientational dynamics of water in carbon nanotubes has been studied by quasi-elastic neutron scattering from 300 down to 10 K. Results show that, reducing temperature below 200 K, part of this water behaves as a quasi-free rotor, that is, the orientational energy of such molecules becomes comparable to the rotational energy of water in the gas phase. This novel and unique dynamic behavior is related to the appearance of water molecules characterized by a coordination number of about two, which is promoted by sub-nanometer axial confinement...
March 22, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28318840/self-reported-sleep-disturbances-associated-with-procedural-learning-impairment-in-adolescents-at-ultra-high-risk-for-psychosis
#2
Jessica R Lunsford-Avery, Derek J Dean, Vijay A Mittal
Sleep disturbance contributes to impaired procedural learning in schizophrenia, yet little is known about this relationship prior to psychosis onset. Adolescents at ultra high-risk (UHR; N=62) for psychosis completed the Pittsburgh Sleep Quality Index (PSQI) and a procedural learning task (Pursuit Rotor). Increased self-reported problems with sleep latency, efficiency, and quality were associated with impaired procedural learning rate. Further, within-sample comparisons revealed that UHR youth reporting better sleep displayed a steeper learning curve than those with poorer sleep...
March 16, 2017: Schizophrenia Research
https://www.readbyqxmd.com/read/28303802/rotation-excited-perfect-oscillation-of-a-tri-walled-nanotube-based-oscillator-at-ultralow-temperature
#3
Kun Cai, Xiaoni Zhang, Jiao Shi, Qing H Qin
In recent years, carbon-nanotube (CNT)-based gigahertz oscillators have been widely used in numerous areas of practical engineering such as high-speed digital, analog circuits, and memory cells. One of the major challenges to practical applications of the gigahertz oscillator is generating a stable oscillation process from the gigahertz oscillators and then maintaining the stable process for a specified period of time. To address this challenge, an oscillator from a triple-walled CNT-based rotary system is proposed and analyzed numerically in this paper, using a molecular dynamics approach...
April 18, 2017: Nanotechnology
https://www.readbyqxmd.com/read/28298110/near-infrared-overtone-voh-2-%C3%A2-0-spectroscopy-of-ne-h2o-clusters
#4
Michael P Ziemkiewicz, Christian Pluetzer, Michael Wojcik, Jérôme Loreau, Ad van der Avoird, David J Nesbitt
Vibrationally state selective overtone spectroscopy and dynamics of weakly bound Ne-H2O complexes (D0((para)) = 31.67 cm(-1), D0((ortho)) = 34.66 cm(-1)) are reported for the first time, based on near infrared excitation of van der Waals cluster bands correlating with vOH = 2 ← 0 overtone transitions (|02(-)⟩←|00(+)⟩ and |02(+)⟩←|00(+)⟩) out of the ortho (101) and para (000) internal rotor states of the H2O moiety. Quantum theoretical calculations for nuclear motion on a high level ab initio potential energy surface (CCSD(T)/VnZ-f12 (n = 3,4), corrected for basis set superposition error and extrapolated to the complete basis set limit) are employed for assignment of Σ←Σ,Π←Σ, and Σ←Π infrared bands in the overtone spectra, where Σ(K = 0) and Π (K = 1) represent approximate projections (K) of the body angular momentum along the Ne-H2O internuclear axis...
March 14, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28297908/kink-antikink-asymmetry-and-impurity-interactions-in-topological-mechanical-chains
#5
Yujie Zhou, Bryan Gin-Ge Chen, Nitin Upadhyaya, Vincenzo Vitelli
We study the dynamical response of a diatomic periodic chain of rotors coupled by springs, whose unit cell breaks spatial inversion symmetry. In the continuum description, we derive a nonlinear field theory which admits topological kinks and antikinks as nonlinear excitations but where a topological boundary term breaks the symmetry between the two and energetically favors the kink configuration. Using a cobweb plot, we develop a fixed-point analysis for the kink motion and demonstrate that kinks propagate without the Peierls-Nabarro potential energy barrier typically associated with lattice models...
February 2017: Physical Review. E
https://www.readbyqxmd.com/read/28289229/persistence-of-the-mitochondrial-permeability-transition-in-the-absence-of-subunit-c-of-human-atp-synthase
#6
Jiuya He, Holly C Ford, Joe Carroll, Shujing Ding, Ian M Fearnley, John E Walker
The permeability transition in human mitochondria refers to the opening of a nonspecific channel, known as the permeability transition pore (PTP), in the inner membrane. Opening can be triggered by calcium ions, leading to swelling of the organelle, disruption of the inner membrane, and ATP synthesis, followed by cell death. Recent proposals suggest that the pore is associated with the ATP synthase complex and specifically with the ring of c-subunits that constitute the membrane domain of the enzyme's rotor...
March 13, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28285456/is-vf-an-ablatable-rhythm
#7
REVIEW
Ghassen Cheniti, Meleze Hocini, Ruairidh Martin, Frederic Sacher, Remi Dubois, Michel Haissaguerre, Pierre Jais
Ventricular fibrillation (VF) has traditionally been considered to be a disorganized arrhythmia not amenable to catheter ablation. However, a better understanding of the VF pathophysiology has allowed identification of targets for ablation. Ablation targeting the premature ventricular complexes which trigger VF was proven to be associated with high success rates and long-term freedom from VF recurrence. Recent mapping data has identified rotors, focal breakthroughs, and figure of eight re-entries as main drivers maintaining human VF...
February 2017: Current Treatment Options in Cardiovascular Medicine
https://www.readbyqxmd.com/read/28283532/molecular-architecture-of-the-n-type-atpase-rotor-ring-from-burkholderia-pseudomallei
#8
Sarah Schulz, Martin Wilkes, Deryck J Mills, Werner Kühlbrandt, Thomas Meier
The genome of the highly infectious bacterium Burkholderia pseudomallei harbors an atp operon that encodes an N-type rotary ATPase, in addition to an operon for a regular F-type rotary ATPase. The molecular architecture of N-type ATPases is unknown and their biochemical properties and cellular functions are largely unexplored. We studied the B. pseudomallei N1No-type ATPase and investigated the structure and ion specificity of its membrane-embedded c-ring rotor by single-particle electron cryo-microscopy. Of several amphiphilic compounds tested for solubilizing the complex, the choice of the low-density, low-CMC detergent LDAO was optimal in terms of map quality and resolution...
March 10, 2017: EMBO Reports
https://www.readbyqxmd.com/read/28282592/development-of-an-automaton-model-of-rotational-activity-driving-atrial-fibrillation
#9
E J Ciaccio, A B Biviano, E Y Wan, N S Peters, H Garan
BACKGROUND: Atrial fibrillation (AF) is difficult to treat effectively, owing to uncertainty in where to best ablate to eliminate arrhythmogenic substrate. A model providing insight into the electrical activation events would be useful to guide catheter ablation strategy. Method A two-dimensional, 576×576 node automaton was developed to simulate atrial electrical activity. The substrate field was altered by the presence of differing refractory period at varying locations. Fibrosis was added in the form of short, randomly positioned lines of conduction block...
March 2, 2017: Computers in Biology and Medicine
https://www.readbyqxmd.com/read/28282493/molecular-and-vibrational-dynamics-in-the-cholesterol-lowering-agent-lovastatin-solid-state-nmr-inelastic-neutron-scattering-and-periodic-dft-study
#10
Paweł Bilski, Kacper Drużbicki, Jacek Jenczyk, Jadwiga Mielcarek, Jan Wąsicki
Molecular and vibrational dynamics of a widely used cholesterol-lowering agent, lovastatin, have been studied by combining nuclear magnetic resonance relaxation experiments ((1)H NMR) with inelastic neutron scattering (INS) and periodic density functional theory modeling (plane-wave DFT). According to a complementary experimental study, lovastatin shows no phase transitions down to cryogenic conditions, while a progressive, stepwise activation of several molecular motions is observed below room temperature...
March 23, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28282154/lyapunov-exponent-and-out-of-time-ordered-correlator-s-growth-rate-in-a-chaotic-system
#11
Efim B Rozenbaum, Sriram Ganeshan, Victor Galitski
It was proposed recently that the out-of-time-ordered four-point correlator (OTOC) may serve as a useful characteristic of quantum-chaotic behavior, because, in the semiclassical limit ℏ→0, its rate of exponential growth resembles the classical Lyapunov exponent. Here, we calculate the four-point correlator C(t) for the classical and quantum kicked rotor-a textbook driven chaotic system-and compare its growth rate at initial times with the standard definition of the classical Lyapunov exponent. Using both quantum and classical arguments, we show that the OTOC's growth rate and the Lyapunov exponent are, in general, distinct quantities, corresponding to the logarithm of the phase-space averaged divergence rate of classical trajectories and to the phase-space average of the logarithm, respectively...
February 24, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28280097/tailoring-porosity-and-rotational-dynamics-in-a-series-of-octacarboxylate-metal-organic-frameworks
#12
Florian Moreau, Daniil I Kolokolov, Alexander G Stepanov, Timothy L Easun, Anne Dailly, William Lewis, Alexander J Blake, Harriott Nowell, Matthew J Lennox, Elena Besley, Sihai Yang, Martin Schröder
Modulation and precise control of porosity of metal-organic frameworks (MOFs) is of critical importance to their materials function. Here we report modulation of porosity for a series of isoreticular octacarboxylate MOFs, denoted MFM-180 to MFM-185, via a strategy of selective elongation of metal-organic cages. Owing to the high ligand connectivity, these MOFs do not show interpenetration, and are robust structures that have permanent porosity. Interestingly, activated MFM-185a shows a high Brunauer-Emmett-Teller (BET) surface area of 4,734 m(2) g(-1) for an octacarboxylate MOF...
March 9, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28279293/catheter-ablation-of-rotors-for-the-treatment-of-af-should-we-drink-the-kool-aid
#13
EDITORIAL
Srinivas R Dukkipati, Vivek Y Reddy
No abstract text is available yet for this article.
March 14, 2017: Journal of the American College of Cardiology
https://www.readbyqxmd.com/read/28279291/clinical-benefit-of-ablating-localized-sources-for-human-atrial-fibrillation-the-indiana-university-firm-registry
#14
John M Miller, Vikas Kalra, Mithilesh K Das, Rahul Jain, Jason B Garlie, Jordan A Brewster, Gopi Dandamudi
BACKGROUND: Mounting evidence shows that localized sources maintain atrial fibrillation (AF). However, it is unclear in unselected "real-world" patients if sources drive persistent atrial fibrillation (PeAF), long-standing persistent atrial fibrillation (LPeAF), or paroxysmal atrial fibrillation (PAF); if right atrial sites are important; and what the long-term success of source ablation is. OBJECTIVES: The aim of this study was to analyze the role of rotors and focal sources in a large academic registry of consecutive patients undergoing source mapping for AF...
March 14, 2017: Journal of the American College of Cardiology
https://www.readbyqxmd.com/read/28269068/identification-and-annotation-of-multiple-periodic-pulse-trains-using-dominant-frequency-and-graph-search-applications-in-atrial-fibrillation-rotor-detection
#15
Rupin Dalvi, Adrian Suszko, Vijay S Chauhan
Biological signals, such as intracardiac electrograms during atrial fibrillation (AF), can contain multiple periodic components or peaks. We propose a method for identifying individual periodic peak trains in signals containing multiple such periodic sequences. We use dominant frequency-based periodicity detection along with a graph search algorithm to identify the most dominant periodic activation set or peaks of interest. We then remove these peaks and iterate until all periodic sequences are identified. The proposed method is tested on simulated AF intra-cardiac electrograms with periodic activation trains of three distinct frequencies corrupted by noise and complex aperiodic signal features...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28269048/an-algorithm-for-rotor-tracking-in-atrial-fibrillation-using-graph-search-based-periodic-peak-detection
#16
Rupin Dalvi, Adrian Suszko, Vijay S Chauhan
Rotors are rotating electrical waves that may sustain atrial fibrillation (AF); thereby providing therapeutic targets for catheter ablation. We propose a method for identifying rotors from circular catheter recordings of bipolar intracardiac electrograms (EGM) during AF. We use dominant frequency-based periodicity detection along with a graph search algorithm to identify the most dominant periodic activations or peaks of interest in each bipolar EGM recorded by a multipolar circular catheter. We then track the activations across catheter bipoles to determine whether they conform to the rotational pattern of a rotor...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28268380/a-novel-catheter-guidance-algorithm-for-localization-of-atrial-fibrillation-rotor-and-focal-sources
#17
Anthony J Salmin, Prasanth Ganesan, Kristina E Shillieto, Elizabeth M Cherry, David T Huang, Arkady M Pertsov, Behnaz Ghoraani
Locating atrial fibrillation (AF) focal and rotor sources can help improve target ablation therapy for AF. However, it remains unclear how to use the information provided by multi-polar diagnostic catheters (MPDC) to locate AF sources. Our aim was to develop a catheter-guidance algorithm to locate AF focal and rotor sources using a conventional MPDC. We simulated a 10 cm × 10 cm atrial tissue with focal and rotor sources using the Nygren et al. ionic model. We modeled a Lasso MPDC with 20-unipole electrodes placed with a spacing of 4...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28268379/kurtosis-as-a-statistical-approach-to-identify-the-pivot-point-of-the-rotor
#18
Shivaram P Arunachalam, Elizabeth M Annoni, Siva K Mulpuru, Paul A Friedman, Elena G Tolkacheva
Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia that causes stroke affecting more than 2.3 million people in the US. Catheter ablation to terminate AF is successful for paroxysmal AF but suffers limitations with persistent AF patients as current mapping methods cannot identify AF active substrates outside of pulmonary vein region. In this work, we developed a novel Kurtosis based mapping technique that can accurately identify pivot points of the rotors that were induced in ex-vivo isolated rabbit heart...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28268378/development-of-a-novel-probabilistic-algorithm-for-localization-of-rotors-during-atrial-fibrillation
#19
Prasanth Ganesan, Anthony Salmin, Elizabeth M Cherry, Behnaz Ghoraani
Atrial fibrillation (AF) is an irregular heart rhythm that can lead to stroke and other heart-related complications. Catheter ablation has been commonly used to destroy triggering sources of AF in the atria and consequently terminate the arrhythmia. However, efficient and accurate localization of the AF sustaining sources known as rotors is a major challenge in catheter ablation. In this paper, we developed a novel probabilistic algorithm that can adaptively guide a Lasso diagnostic catheter to locate the center of a rotor...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28265026/non-steady-wind-turbine-response-to-daytime-atmospheric-turbulence
#20
Tarak N Nandi, Andreas Herrig, James G Brasseur
Relevant to drivetrain bearing fatigue failures, we analyse non-steady wind turbine responses from interactions between energy-dominant daytime atmospheric turbulence eddies and the rotating blades of a GE 1.5 MW wind turbine using a unique dataset from a GE field experiment and computer simulation. Time-resolved local velocity data were collected at the leading and trailing edges of an instrumented blade together with generator power, revolutions per minute, pitch and yaw. Wind velocity and temperature were measured upwind on a meteorological tower...
April 13, 2017: Philosophical Transactions. Series A, Mathematical, Physical, and Engineering Sciences
keyword
keyword
107224
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"