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https://www.readbyqxmd.com/read/28641397/myocardial-scar-location-as-detected-by-cardiac-magnetic-resonance-is-associated-with-the-outcome-in-heart-failure-patients-undergoing-surgical-ventricular-reconstruction
#1
Serenella Castelvecchio, Giulia Careri, Federico Ambrogi, Antonia Camporeale, Lorenzo Menicanti, Francesco Secchi, Massimo Lombardi
OBJECTIVES: Post-infarction myocardial scar causes adverse left ventricular remodelling and negatively affects the prognosis. We sought to investigate whether scar extent and location obtained by cardiac magnetic resonance may affect the reverse remodelling and survival of heart failure patients undergoing surgical ventricular reconstruction. METHODS: From January 2011 to December 2015, 151 consecutive patients with previous myocardial infarction and left ventricular remodelling underwent surgical ventricular reconstruction at our Institution, of which 88 (58%) patients had a preoperative protocol-standardized late gadolinium enhancement (LGE)-cardiac magnetic resonance examination during the week before surgery...
June 21, 2017: European Journal of Cardio-thoracic Surgery
https://www.readbyqxmd.com/read/28641254/sparse-image-reconstruction-on-the-sphere-analysis-and-synthesis
#2
Christopher G R Wallis, Yves Wiaux, Jason D McEwen
We develop techniques to solve ill-posed inverse problems on the sphere by sparse regularisation, exploiting sparsity in both axisymmetric and directional scale-discretised wavelet space. Denoising, inpainting, and deconvolution problems, and combinations thereof, are considered as examples. Inverse problems are solved in both the analysis and synthesis settings, with a number of different sampling schemes. The most effective approach is that with the most restricted solution-space, which depends on the interplay between the adopted sampling scheme, the selection of the analysis/synthesis problem, and any weighting of the ℓ1 norm appearing in the regularisation problem...
June 16, 2017: IEEE Transactions on Image Processing: a Publication of the IEEE Signal Processing Society
https://www.readbyqxmd.com/read/28641160/effects-of-hip-joint-centre-mislocation-on-gait-kinematics-of-children-with-cerebral-palsy-calculated-using-patient-specific-direct-and-inverse-kinematic-models
#3
Hans Kainz, Christopher P Carty, Sheanna Maine, Henry P J Walsh, David G Lloyd, Luca Modenese
Joint kinematics can be calculated by Direct Kinematics (DK), which is used in most clinical gait laboratories, or Inverse Kinematics (IK), which is mainly used for musculoskeletal research. In both approaches, joint centre locations are required to compute joint angles. The hip joint centre (HJC) in DK models can be estimated using predictive or functional methods, while in IK models can be obtained by scaling generic models. The aim of the current study was to systematically investigate the impact of HJC location errors on lower limb joint kinematics of a clinical population using DK and IK approaches...
June 4, 2017: Gait & Posture
https://www.readbyqxmd.com/read/28641142/optical-electrical-and-ferromagnetic-studies-of-zno-fe-diluted-magnetic-semiconductor-nanoparticles-for-spintronic-applications
#4
R Elilarassi, G Chandrasekaran
In the present investigation, diluted magnetic semiconductor (Zn1-xFexO) nanoparticles with different doping concentrations (x=0, 0.02, 0.04, 0.06, and 0.08) were successfully synthesized by sol-gel auto-combustion method. The crystal structure, morphology, optical, electrical and magnetic properties of the prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive analysis using x-rays (EDAX), ultraviolet-visible spectrophotometer, fluorescence spectroscope (FS), vibrating sample magnetometer (VSM) and broad band dielectric spectrometer (BDS)...
May 31, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28641089/combined-time-lapse-magnetic-resonance-imaging-and-modeling-to-investigate-colloid-deposition-and-transport-in-porous-media
#5
Alizée P Lehoux, Pamela Faure, François Lafolie, Stéphane Rodts, Denis Courtier-Murias, Philippe Coussot, Eric Michel
Colloidal particles can act as vectors of adsorbed pollutants in the subsurface, or be themselves pollutants. They can reach the aquifer and impair groundwater quality. The mechanisms of colloid transport and deposition are often studied in columns filled with saturated porous media. Time-lapse profiles of colloid concentration inside the columns have occasionally been derived from magnetic resonance imaging (MRI) data recorded in transport experiments. These profiles are valuable, in addition to particle breakthrough curves (BTCs), for testing and improving colloid transport models...
June 14, 2017: Water Research
https://www.readbyqxmd.com/read/28641000/magnetic-properties-of-the-distorted-kagom%C3%A3-lattice-mn3-1-2-4-o2c-3c6h3-2
#6
Richard A Mole, Stephen Greene, Paul F Henry, Simon M Humphrey, Kirrily C Rule, Tobias Unruh, Gerald F Weldon, Dehong Yu, John A Stride, Paul T Wood
Kagomé lattice types have been of intense interest as idealized examples of extended frustrated spin systems. Here we demonstrate how the use of neutron diffraction and inelastic neutron scattering coupled with spin wave theory calculations can be used to elucidate the complex magnetic interactions of extended spin networks. We show that the magnetic properties of the coordination polymer Mn3(1,2,4-(O2C)3C6H3)2, a highly distorted kagomé lattice, have been erroneously characterized as a canted antiferromagnet in previous works...
June 22, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28640989/stimulant-treatment-trajectories-are-associated-with-neural-reward-processing-in-attention-deficit-hyperactivity-disorder
#7
Lizanne J S Schweren, Annabeth Groenman, Daniel von Rhein, Wouter Weeda, Stephen F Faraone, Marjolein Luman, Hanneke van Ewijk, Dirk J Heslenfeld, Barbara Franke, Jan K Buitelaar, Jaap Oosterlaan, Pieter J Hoekstra, Catharina A Hartman
OBJECTIVE: The past decades have seen a surge in stimulant prescriptions for the treatment of attention-deficit/hyperactivity disorder (ADHD). Stimulants acutely alleviate symptoms and cognitive deficits associated with ADHD by modulating striatal dopamine neurotransmission and induce therapeutic changes in brain activation patterns. Long-term functional changes after treatment are unknown, as long-term studies are scarce and have focused on brain structure. In this observational study (2009-2012), we investigated associations between lifetime stimulant treatment history and neural activity during reward processing...
June 20, 2017: Journal of Clinical Psychiatry
https://www.readbyqxmd.com/read/28640923/how-much-detail-is-needed-in-modeling-a-transcranial-magnetic-stimulation-figure-8-coil-measurements-and-brain-simulations
#8
Petar I Petrov, Stefano Mandija, Iris E C Sommer, Cornelis A T van den Berg, Sebastiaan F W Neggers
BACKGROUND: Despite TMS wide adoption, its spatial and temporal patterns of neuronal effects are not well understood. Although progress has been made in predicting induced currents in the brain using realistic finite element models (FEM), there is little consensus on how a magnetic field of a typical TMS coil should be modeled. Empirical validation of such models is limited and subject to several limitations. METHODS: We evaluate and empirically validate models of a figure-of-eight TMS coil that are commonly used in published modeling studies, of increasing complexity: simple circular coil model; coil with in-plane spiral winding turns; and finally one with stacked spiral winding turns...
2017: PloS One
https://www.readbyqxmd.com/read/28640874/risk-factors-are-different-for-deep-and-lobar-remote-hemorrhages-after-intravenous-thrombolysis
#9
Luis Prats-Sanchez, Alejandro Martínez-Domeño, Pol Camps-Renom, Raquel Delgado-Mederos, Daniel Guisado-Alonso, Rebeca Marín, Laura Dorado, Salvatore Rudilosso, Alejandra Gómez-González, Francisco Purroy, Manuel Gómez-Choco, David Cánovas, Dolores Cocho, Moises Garces, Sonia Abilleira, Joan Martí-Fàbregas
BACKGROUND AND PURPOSE: Remote parenchymal haemorrhage (rPH) after intravenous thrombolysis is defined as hemorrhages that appear in brain regions without visible ischemic damage, remote from the area of ischemia causing the initial stroke symptom. The pathophysiology of rPH is not clear and may be explained by different underlying mechanisms. We hypothesized that rPH may have different risk factors according to the bleeding location. We report the variables that we found associated with deep and lobar rPH after intravenous thrombolysis...
2017: PloS One
https://www.readbyqxmd.com/read/28640873/healthy-aging-of-the-left-ventricle-in-relationship-to-cardiovascular-risk-factors-the-multi-ethnic-study-of-atherosclerosis-mesa
#10
Chia-Ying Liu, Shenghan Lai, Nadine Kawel-Boehm, Harjit Chahal, Bharath Ambale-Venkatesh, Joao A C Lima, David A Bluemke
BACKGROUND: Understanding the relationship of cardiovascular structure and function to age is confounded by the high prevalence of traditional risk factors in the United States. The purpose of the study is to compare left ventricular (LV) and aortic structural, and functional parameters in individuals with and without traditional risk factors in a population-based cohort. METHODS AND RESULTS: 3015 study participants (48% men, age 55-94, mean 69.01±9.17 years) in the Multi-Ethnic Study of Atherosclerosis (MESA) underwent cardiovascular magnetic resonance (CMR) imaging from 2010-2012...
2017: PloS One
https://www.readbyqxmd.com/read/28640847/heart-rate-lowering-treatment-leads-to-a-reduction-in-vulnerable-plaque-features-in-atherosclerotic-rabbits
#11
Raf H M van Hoof, Evelien Hermeling, Judith C Sluimer, Julie Salzmann, Arnold P G Hoeks, Jérôme Roussel, Mat J A P Daemen, Harry Struijker-Boudier, Joachim E Wildberger, Sylvia Heeneman, M Eline Kooi
OBJECTIVE: To investigate the effect of a heart rate (HR) lowering agent (Ivabradine) on features of atherosclerotic plaque vulnerability with magnetic resonance imaging (MRI), ultrasound imaging, and histology. APPROACH AND RESULTS: Atherosclerosis was induced in the abdominal aorta of 19 rabbits. Nine rabbits were treated with Ivabradine (17 mg/kg/day) during the entire study period. At week 14, imaging was performed. Plaque size was quantified on contrast-enhanced T1-weighted MR images...
2017: PloS One
https://www.readbyqxmd.com/read/28640757/novel-domain-wall-dynamics-in-synthetic-antiferromagnets
#12
See-Hun Yang, Stuart Parkin
In this article, we review fascinating new mechanisms on recently observed remarkable current driven domain wall motion in nanowires formed from perpendicularly magnetized synthetic antiferromagnets interfaced with heavy metallic layers, sources of spin-orbit torques. All the associated torques such as volumetric adiabatic and non-adiabatic spin-transfer-torque, spin-orbit torques, shape anisotropy field torques, Dzyaloshinkii-Moriya interaction torques and most importantly a new powerful torque, exchange coupling torque, will be discussed based on an analytical model that provides an intuitive description of domain wall dynamics in synthetic ferromagnets as well as synthetic antiferromagnets...
June 22, 2017: Journal of Physics. Condensed Matter: An Institute of Physics Journal
https://www.readbyqxmd.com/read/28640699/brain-tumor-imaging
#13
Kevin M Brindle, José L Izquierdo-García, David Y Lewis, Richard J Mair, Alan J Wright
Modern imaging techniques, particularly functional imaging techniques that interrogate some specific aspect of underlying tumor biology, have enormous potential in neuro-oncology for disease detection, grading, and tumor delineation to guide biopsy and resection; monitoring treatment response; and targeting radiotherapy. This brief review considers the role of magnetic resonance imaging and spectroscopy, and positron emission tomography in these areas and discusses the factors that limit translation of new techniques to the clinic, in particular, the cost and difficulties associated with validation in multicenter clinical trials...
June 22, 2017: Journal of Clinical Oncology: Official Journal of the American Society of Clinical Oncology
https://www.readbyqxmd.com/read/28640695/gadolinium-brain-deposition-after-macrocyclic-gadolinium-administration-a-pediatric-case-control-study
#14
Daniel Tibussek, Christin Rademacher, Julian Caspers, Bernd Turowski, Jörg Schaper, Gerald Antoch, Dirk Klee
Purpose To determine whether signal intensity (SI) in T1 sequences as a potential indicator of gadolinium deposition increases after repeated administration of the macrocyclic gadolinium-based contrast agents (GBCAs) gadoteridol and gadoterate meglumine in a pediatric cohort. Materials and Methods This retrospective case-control study of children with brain tumors who underwent nine or more contrast material-enhanced brain magnetic resonance (MR) imaging studies from 2008 to 2015 was approved by the local ethics board...
June 21, 2017: Radiology
https://www.readbyqxmd.com/read/28640692/comparison-of-gadolinium-concentrations-within-multiple-rat-organs-after-intravenous-administration-of-linear-versus-macrocyclic-gadolinium-chelates
#15
Robert J McDonald, Jennifer S McDonald, Daying Dai, Dana Schroeder, Mark E Jentoft, David L Murray, Ramanathan Kadirvel, Laurence J Eckel, David F Kallmes
Purpose To compare gadolinium tissue concentrations of multiple linear and macrocyclic chelates in a rat model to better understand the scope and extent of tissue deposition following multiple intravenous doses of gadolinium-based contrast agent (GBCA). Materials and Methods In this Institutional Animal Care and Use Committee-approved study, healthy rats received 20 intravenous injections of 2.5 mmol gadolinium per kilogram (gadolinium-exposed group) or saline (control group) over a 26-day period. Unenhanced T1 signal intensities of the dentate nucleus were measured from magnetic resonance (MR) images obtained prior to GBCA injection and 3 days after final injection...
June 19, 2017: Radiology
https://www.readbyqxmd.com/read/28640633/exploring-a-proximity-coupled-co-chain-on-pb-110-as-a-possible-majorana-platform
#16
Michael Ruby, Benjamin Wilhelm Heinrich, Yang Peng, Felix von Oppen, Katarina Franke
Linear chains of magnetic atoms proximity coupled to an s-wave superconductor are predicted to host Majorana zero modes at the chain ends in the presence of strong spin-orbit coupling. Specically, iron chains on Pb(110) have been explored as a possible system to exhibit topological superconductivity and host Majorana zero-modes [Nadj-Perge, et al., Science 346 (2014)]. Here, we study chains of the transition metal cobalt on Pb(110) and check for topological signatures. Using spin-polarized scanning tunneling spectroscopy, we resolve ferromagnetic order in the d bands of the chains...
June 22, 2017: Nano Letters
https://www.readbyqxmd.com/read/28640605/high-pressure-synthesis-crystal-structure-and-magnetic-and-transport-properties-of-a-six-layered-srrho3
#17
Yan Li, Jinguang Cheng, José Antonio Alonso, John B Goodenough, Jianshi Zhou
A SrRhO3 polytype with six-layered (6M) structure was synthesized under high pressure and high temperature. The crystal structure was obtained by refining X-ray powder diffraction with the monoclinic space group C2/c with lattice parameters a = 5.5650(1) Å, b = 9.5967(2) Å, c = 14.0224(4) Å, and β = 92.846(2)°. It is isostructural with SrIrO3 synthesized under ambient pressure and consists of dimers of the face-shared Rh(2)O6 octahedra connected by their vertices to the corner-shared Rh(1)O6 octahedra along the c axis with a stacking of SrO3 layers in the sequence of CCHCCH, where C and H denote cubic and hexagonal closed packing, respectively...
June 22, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28640598/structural-and-light-absorption-characteristics-of-complex-water-insoluble-organic-mixtures-in-urban-submicron-aerosols
#18
Qingcai Chen, Fumikazu Ikemori, Yuua Nakamura, Petr Vodicka, Kimitaka Kawamura, Michihiro Mochida
Submicrometer aerosols in the urban atmosphere of Nagoya, Japan, were collected in late winter and early spring, and the water-insoluble organic matter (WISOM) in the samples were fractionated into six subfractions based on their polarities by using solvent and normal-phase solid-phase extractions: non-polar (F1), low-polar (F2 and F3), and medium-polar (F4, F5, and F6) fractions. The overall structural characteristics of these subfractions were then analyzed using Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, and high-resolution aerosol mass spectrometry...
June 22, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28637289/the-importance-of-knowing-when-you-don-t-remember-neural-signaling-of-retrieval-failure-predicts-memory-improvement-over-time
#19
Yana Fandakova, Silvia A Bunge, Carter Wendelken, Peter Desautels, Lauren Hunter, Joshua K Lee, Simona Ghetti
Just as the ability to remember prior events is critical for guiding our decision-making, so too is the ability to recognize the limitations of our memory. Indeed, we hypothesize that neural signaling of retrieval failure promotes more accurate memory judgments over time. To test this hypothesis, we collected longitudinal functional magnetic resonance imaging data from 8 to 9 years olds, 10 to 12 years olds, and adults, with two time points spaced approximately 1.4 years apart (198 scan sessions in total)...
November 23, 2016: Cerebral Cortex
https://www.readbyqxmd.com/read/28637279/high-dimensional-multivariate-mediation-with-application-to-neuroimaging-data
#20
Oliver Y Chén, Ciprian Crainiceanu, Elizabeth L Ogburn, Brian S Caffo, Tor D Wager, Martin A Lindquist
Mediation analysis is an important tool in the behavioral sciences for investigating the role of intermediate variables that lie in the path between a treatment and an outcome variable. The influence of the intermediate variable on the outcome is often explored using a linear structural equation model (LSEM), with model coefficients interpreted as possible effects. While there has been significant research on the topic, little work has been done when the intermediate variable (mediator) is a high-dimensional vector...
June 15, 2017: Biostatistics
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