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https://www.readbyqxmd.com/read/28102875/prevalence-of-abnormal-electrocardiograms-in-swiss-elite-athletes-detected-with-modern-screening-criteria
#1
Tilman Perrin, Lukas Daniel Trachsel, Simon Schneiter, Andrea Menafoglio, Silvia Albrecht, Tony Pirrello, Prisca Eser, Laurent Roten, Boris Gojanovic, Matthias Wilhelm
AIMS OF THE STUDY: Sudden cardiac arrest in athletes is a rare but dramatic event. The value of a routine electrocardiogram (ECG) during preparticipation screening (PPS) remains controversial, partly because of the relatively high number of false positive findings. Our study aimed to evaluate the prevalence of abnormal ECGs in consecutive Swiss elite athletes, overall and with regard to different sports classes, using modern screening criteria. METHODS: We analysed the 12-lead resting ECGs of high-level elite athletes (age ≥14 years) recorded at the Swiss Olympic Medical Centre Magglingen between 2013 and 2016 during routine PPS...
January 19, 2017: Swiss Medical Weekly
https://www.readbyqxmd.com/read/28088152/theoretical-description-of-circular-dichroism-in-photoelectron-angular-distributions-of-randomly-oriented-chiral-molecules-after-multi-photon-photoionization
#2
R E Goetz, T A Isaev, B Nikoobakht, R Berger, C P Koch
Photoelectron circular dichroism refers to the forward/backward asymmetry in the photoelectron angular distribution with respect to the propagation axis of circularly polarized light. It has recently been demonstrated in femtosecond multi-photon photoionization experiments with randomly oriented camphor and fenchone molecules [C. Lux et al., Angew. Chem., Int. Ed. 51, 4755 (2012) and C. S. Lehmann et al., J. Chem. Phys. 139, 234307 (2013)]. A theoretical framework describing this process as (2+1) resonantly enhanced multi-photon ionization is constructed, which consists of two-photon photoselection from randomly oriented molecules and successive one-photon ionization of the photoselected molecules...
January 14, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28069573/relations-between-aortic-stiffness-and-left-ventricular-mechanical-function-in-the-community
#3
Vanessa Bell, Elizabeth L McCabe, Martin G Larson, Jian Rong, Allison A Merz, Ewa Osypiuk, Birgitta T Lehman, Plamen Stantchev, Jayashri Aragam, Emelia J Benjamin, Naomi M Hamburg, Ramachandran S Vasan, Gary F Mitchell, Susan Cheng
BACKGROUND: Aortic stiffness impairs optimal ventricular-vascular coupling and left ventricular systolic function, particularly in the long axis. Left ventricular global longitudinal strain (GLS) has recently emerged as a sensitive measure of early cardiac dysfunction. In this study, we investigated the relation between aortic stiffness and GLS in a large community-based sample. METHODS AND RESULTS: In 2495 participants (age 39-90 years, 57% women) of the Framingham Offspring and Omni cohorts, free of cardiovascular disease, we performed tonometry to measure arterial hemodynamics and echocardiography to assess cardiac function...
January 9, 2017: Journal of the American Heart Association
https://www.readbyqxmd.com/read/28048747/su-f-t-230-a-simple-method-to-assess-accuracy-of-dynamic-wave-arc-irradiation-using-an-electronic-portal-imaging-device-and-log-files
#4
H Hirashima, Y Miyabe, K Yokota, M Nakamura, N Mukumoto, T Mizowaki, M Hiraoka
PURPOSE: The Dynamic Wave Arc (DWA) technique, where the multi-leaf collimator (MLC) and gantry/ring move simultaneously in a predefined non-coplanar trajectory, has been developed on the Vero4DRT. The aim of this study is to develop a simple method for quality assurance of DWA delivery using an electronic portal imaging device (EPID) measurements and log files analysis. METHODS: The Vero4DRT has an EPID on the beam axis, the resolution of which is 0.18 mm/pixel at the isocenter plane...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28043038/intra-individual-cortisol-variability-and-low-grade-inflammation-over-10-years-in-older-adults
#5
Heather Herriot, Carsten Wrosch, Jean-Philippe Gouin, Gregory E Miller
OBJECTIVE: This study examined the associations between intra-individual variability in, and inter-individual levels of, diurnal cortisol secretion with a marker of low-grade inflammation (i.e., C-Reactive Protein; CRP). Reasoning that greater day-to-day cortisol variability could reflect a dysregulation of the HPA axis, we hypothesized that it would predict higher levels of CRP, above and beyond inter-individual differences in cortisol levels. METHODS: A 10-year longitudinal study of 130 older adults examined diurnal cortisol secretion on three different days across each of the 6 waves of data collection and levels of CRP during the last 3 waves...
December 21, 2016: Psychoneuroendocrinology
https://www.readbyqxmd.com/read/28011834/impact-of-mechanical-deformation-on-pseudo-ecg-a-simulation-study
#6
Marco Favino, Sonia Pozzi, Simone Pezzuto, Frits W Prinzen, Angelo Auricchio, Rolf Krause
AIMS: Electrophysiological simulations may help to investigate causes and possible treatments of ventricular conduction disturbances. Most electrophysiological models do not take into account that the heart moves during the cardiac cycle. We used an electro-mechanical model to study the effect of mechanical deformation on the results of electrophysiological simulations. METHODS AND RESULTS: Pseudo-electrocardiogram (ECG) were generated from the propagation of electrical signals in tissue slabs undergoing active mechanical deformation...
December 2016: Europace: European Pacing, Arrhythmias, and Cardiac Electrophysiology
https://www.readbyqxmd.com/read/27834978/light-scattering-study-of-the-pseudo-layer-compression-elastic-constant-in-a-twist-bend-nematic-liquid-crystal
#7
Z Parsouzi, Shokir A Pardaev, C Welch, Z Ahmed, G H Mehl, A R Baldwin, J T Gleeson, O D Lavrentovich, D W Allender, J V Selinger, A Jakli, S Sprunt
The nematic twist-bend (TB) phase, exhibited by certain achiral thermotropic liquid crystalline (LC) dimers, features a nanometer-scale, heliconical rotation of the average molecular long axis (director) with equally probable left- and right-handed domains. On meso to macroscopic scales, the TB phase may be considered as a stack of equivalent slabs or "pseudo-layers", each one helical pitch in thickness. The long wavelength fluctuation modes should then be analogous to those of a smectic-A phase, and in particular the hydrodynamic mode combining "layer" compression and bending ought to be characterized by an effective layer compression elastic constant Beff and average director splay constant K...
November 11, 2016: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/27795576/squirmers-with-swirl-a-model-for-volvox-swimming
#8
T J Pedley, D R Brumley, R E Goldstein
Colonies of the green alga Volvox are spheres that swim through the beating of pairs of flagella on their surface somatic cells. The somatic cells themselves are mounted rigidly in a polymeric extracellular matrix, fixing the orientation of the flagella so that they beat approximately in a meridional plane, with axis of symmetry in the swimming direction, but with a roughly [Formula: see text] azimuthal offset which results in the eponymous rotation of the colonies about a body-fixed axis. Experiments on colonies of Volvox carteri held stationary on a micropipette show that the beating pattern takes the form of a symplectic metachronal wave (Brumley et al...
July 10, 2016: Journal of Fluid Mechanics
https://www.readbyqxmd.com/read/27772664/follow-up-of-electrocardiographic-findings-and-arrhythmias-in-patients-with-anomalously-arising-left-coronary-artery-from-the-pulmonary-trunk
#9
Judson A Moore, Antonio G Cabrera, Jeffrey J Kim, Santiago O Valdés, Caridad de la Uz, Christina Y Miyake
Follow-up data and correlation of arrhythmias, electrocardiogram (ECG) changes, and cardiac function in anomalous left coronary artery from the pulmonary trunk or artery have not been previously studied. This is a retrospective single-center review of 44 anomalous left coronary artery from the pulmonary trunk or artery patients diagnosed between 1992 and 2014, at a median age of 3 months (3 days to 13 years). Clinical history, ECG, Holter, and echocardiogram data were reviewed. ECGs were reviewed for contiguous Q-or T-wave inversions, hypertrophy, bundle branch block, and axis deviation...
September 23, 2016: American Journal of Cardiology
https://www.readbyqxmd.com/read/27718376/helical-comb-magnetostrictive-patch-transducers-for-inspecting-spiral-welded-pipes-using-flexural-guided-waves
#10
Xiaowei Zhang, Zhifeng Tang, Fuzai Lv, Xiaohong Pan
A wavefront analysis indicates that a flexural wave propagates at a helix angle with respect to the pipe axis. The expression for calculation of the helix angle for each flexural mode is given, and the helix angle dispersion curves for flexural modes are calculated. According to the new understanding of flexural guided waves, a helical comb magnetostrictive patch transducer (HCMPT) is proposed for selectively exciting a single predominant flexural torsional guided wave in a pipe and inspecting spiral welded pipes using flexural waves...
February 2017: Ultrasonics
https://www.readbyqxmd.com/read/27670068/canine-pulmonary-vein-to-pulmonary-artery-ratio-echocardiographic-technique-and-reference-intervals
#11
F Birettoni, D Caivano, V Patata, N S Moïse, C Guglielmini, M Rishniw, F Porciello
OBJECTIVES: The size of the pulmonary veins (PVs) and pulmonary arteries (PAs) changes in response to hemodynamic alterations caused by physiological events and disease. We sought to create standardized echocardiographic methods for imaging the right ostium of the pulmonary veins (RPVs) and the right pulmonary artery (RPA) using specific landmarks and timing to quantify vessel diameters and phasic changes during the cardiac cycle. ANIMALS: Fifty client-owned healthy dogs prospectively recruited...
December 2016: Journal of Veterinary Cardiology: the Official Journal of the European Society of Veterinary Cardiology
https://www.readbyqxmd.com/read/27661886/high-gain-87-cm-sup-1-sup-raman-line-of-kyw-and-its-impact-on-continuous-wave-raman-laser-operation
#12
Soumya Sarang, Robert J Williams, Oliver Lux, Ondrej Kitzler, Aaron McKay, Hadiya Jasbeer, Richard P Mildren
We report a quasi-continuous-wave external cavity Raman laser based on potassium yttrium tungstate (KYW). Laser output efficiency and spectrum are severely affected by the presence of high gain Raman modes of low frequency (< 250 cm<sup>-1</sup>) that are characteristic of this crystal class. Output spectra contained frequency combs spaced by the low frequency modes but with the overall pump-to-Stokes conversion efficiency at least an order of magnitude lower than that typically obtained in other crystal Raman lasers...
September 19, 2016: Optics Express
https://www.readbyqxmd.com/read/27661715/superconducting-gap-anisotropy-in-monolayer-fese-thin-film
#13
Y Zhang, J J Lee, R G Moore, W Li, M Yi, M Hashimoto, D H Lu, T P Devereaux, D-H Lee, Z-X Shen
Superconductivity originates from pairing of electrons near the Fermi energy. The Fermi surface topology and pairing symmetry are thus two pivotal characteristics of a superconductor. Superconductivity in one monolayer (1 ML) FeSe thin film has attracted great interest recently due to its intriguing interfacial properties and possibly high superconducting transition temperature over 65 K. Here, we report high-resolution measurements of the Fermi surface and superconducting gaps in 1 ML FeSe using angle-resolved photoemission spectroscopy...
September 9, 2016: Physical Review Letters
https://www.readbyqxmd.com/read/27622525/aspect-ratio-driven-evolution-of-high-order-resonant-modes-and-near-field-distributions-in-localized-surface-phonon-polariton-nanostructures
#14
Chase T Ellis, Joseph G Tischler, Orest J Glembocki, Francisco J Bezares, Alexander J Giles, Richard Kasica, Loretta Shirey, Jeffrey C Owrutsky, Dmitry N Chigrin, Joshua D Caldwell
Polar dielectrics have garnered much attention as an alternative to plasmonic metals in the mid- to long-wave infrared spectral regime due to their low optical losses. As such, nanoscale resonators composed of these materials demonstrate figures of merit beyond those achievable in plasmonic equivalents. However, until now, only low-order, phonon-mediated, localized polariton resonances, known as surface phonon polaritons (SPhPs), have been observed in polar dielectric optical resonators. In the present work, we investigate the excitation of 16 distinct high-order, multipolar, localized surface phonon polariton resonances that are optically excited in rectangular pillars etched into a semi-insulating silicon carbide substrate...
2016: Scientific Reports
https://www.readbyqxmd.com/read/27604657/electrocardiographic-detection-of-hypertensive-left-atrial-enlargement-in-the-presence-of-obesity-re-calibration-against-cardiac-magnetic-resonance
#15
J C L Rodrigues, T Erdei, A G Dastidar, B McIntyre, A E Burchell, L E K Ratcliffe, E C Hart, M C K Hamilton, J F R Paton, A K Nightingale, N E Manghat
Left atrial enlargement (LAE) has adverse prognostic implications in hypertension. We sought to determine the accuracy of five electrocardiogram (ECG) criteria for LAE in hypertension relative to cardiac magnetic resonance (CMR) gold standard and investigate the effect of concomitant obesity. One hundred and thirty consecutive patients (age: 51.4±15.1 years, 47% male, 51% obese, systolic blood pressure (BP): 171±29 mm Hg, diastolic BP: 97±15 mm Hg) referred for CMR (1.5 T) from a tertiary hypertension clinic were included...
September 8, 2016: Journal of Human Hypertension
https://www.readbyqxmd.com/read/27604150/influence-of-the-spatially-inhomogeneous-gap-distribution-on-the-quasiparticle-current-in-c-axis-junctions-involving-d-wave-superconductors-with-charge-density-waves
#16
T Ekino, A M Gabovich, Mai Suan Li, H Szymczak, A I Voitenko
The quasiparticle tunnel current J(V) between the superconducting ab-planes along the c-axis and the corresponding conductance [Formula: see text] were calculated for symmetric junctions composed of disordered d-wave layered superconductors partially gapped by charge density waves (CDWs). Here, V is the voltage. Both the checkerboard and unidirectional CDWs were considered. It was shown that the spatial spread of the CDW-pairing strength substantially smears the peculiarities of G(V) appropriate to uniform superconductors...
November 9, 2016: Journal of Physics. Condensed Matter: An Institute of Physics Journal
https://www.readbyqxmd.com/read/27474333/moderate-aortic-valvular-insufficiency-invalidates-vortex-formation-time-as-an-index-of-left-ventricular-filling-efficiency-in-patients-with-severe-degenerative-calcific-aortic-stenosis-undergoing-aortic-valve-replacement
#17
Paul S Pagel, Brent T Boettcher, Derek J De Vry, Julie K Freed, Zafar Iqbal
OBJECTIVE: Transmitral blood flow produces a vortex ring (quantified using vortex formation time [VFT]) that enhances the efficiency of left ventricular (LV) filling. VFT is attenuated in LV hypertrophy resulting from aortic valve stenosis (AS) versus normal LV geometry. Many patients with AS also have aortic insufficiency (AI). The authors tested the hypothesis that moderate AI falsely elevates VFT by partially inhibiting mitral leaflet opening in patients with AS. DESIGN: Observational study...
October 2016: Journal of Cardiothoracic and Vascular Anesthesia
https://www.readbyqxmd.com/read/27443474/modified-limb-lead-ecg-system-effects-on-electrocardiographic-wave-amplitudes-and-frontal-plane-axis-in-sinus-rhythm-subjects
#18
Sivaraman Jayaraman, Venkatesan Sangareddi, R Periyasamy, Justin Joseph, Ravi Marimuthu Shanmugam
OBJECTIVE: Modified Limb Lead (MLL) ECG system may be used during rest or exercise ECG, or atrial activity enhancement. Because of modification in the limb electrode placement, changes are likely to happen in ECG wave amplitudes and frontal plane axis, which may alter the clinical limits of normality and ECG diagnostic criteria. The present study investigated the effects of the modified limb electrode position on the electrocardiographic waveforms, ST segment amplitudes (STa) and frontal plane axis...
June 29, 2016: Anatolian Journal of Cardiology
https://www.readbyqxmd.com/read/27433739/properties-of-an-axial-optical-vortex-generated-with-the-use-of-a-gaussian-beam-and-two-ramps
#19
A N Khoroshun, A V Chernykh, A N Tsimbaluk, J A Kirichenko, P V Yezhov, A V Kuzmenko, J T Kim
The behavior of an axial optical vortex (OV), which is generated with the use of a Gaussian beam and two ramps implemented by a phase-only spatial light modulator (SLM), is studied as a function of the parameters of two ramps. The analytic solution of a wave equation is obtained in the Fresnel approximation for the diffraction of a Gaussian beam on the two-ramp structure. Nonlinear dependences of the ellipticity gamma of the intensity distribution in the OV core, as well as the angle (phi between the x-axis and the major ellipse axis of the vortex core, on the ramp phase gradient K, are analyzed...
February 2016: Journal of Nanoscience and Nanotechnology
https://www.readbyqxmd.com/read/27406603/identification-of-concealed-and-manifest-long-qt-syndrome-using-a-novel-t-wave-analysis-program
#20
Alan Sugrue, Peter A Noseworthy, Vaclav Kremen, J Martijn Bos, Bo Qiang, Ram K Rohatgi, Yehu Sapir, Zachi I Attia, Peter Brady, Samuel J Asirvatham, Paul A Friedman, Michael J Ackerman
BACKGROUND: Congenital long QT syndrome (LQTS) is characterized by QT prolongation. However, the QT interval itself is insufficient for diagnosis, unless the corrected QT interval is repeatedly ≥500 ms without an acquired explanation. Further, the majority of LQTS patients have a corrected QT interval below this threshold, and a significant minority has normal resting corrected QT interval values. Here, we aimed to develop and validate a novel, quantitative T wave morphological analysis program to differentiate LQTS patients from healthy controls...
July 2016: Circulation. Arrhythmia and Electrophysiology
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