NICS‐ XY ‐Scan Predictions of Local, Semi‐Global, and Global Ring Currents in Annulated Pentalene and s‐Indacene Cores Compared to First‐Principles Current Density Maps

ChemPhysChem ◽  
2019 ◽  
Vol 21 (1) ◽  
pp. 65-82 ◽  
Author(s):  
Amnon Stanger ◽  
Guglielmo Monaco ◽  
Riccardo Zanasi
Keyword(s):  
Current Density ◽  
First Principles ◽  
Ring Currents ◽  
Density Maps

Current-density maps as probes of aromaticity: Global and Clar π ring currents in totally resonant polycyclic aromatic hydrocarbons

2007 ◽  
Vol 135 ◽  
pp. 309-323 ◽  
Author(s):  
Erich Steiner ◽  
Patrick W. Fowler ◽  
Alessandro Soncini ◽  
Leonardus W. Jenneskens
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Current Density ◽  
Aromatic Hydrocarbons ◽  
Ring Currents ◽  
Density Maps ◽  
Polycyclic Aromatic

scholarly journals Simulation models of current density imaging in studying cardiac states

2021 ◽  
Author(s):  
Mohammadali Beheshti
Keyword(s):  
Cardiac Function ◽  
Electrical Activity ◽  
Current Density ◽  
Diffusion Tensor ◽  
Model Simulation ◽  
Correlation Coefficients ◽  
Biological Tissues ◽  
Density Maps ◽  
Current Density Imaging ◽  
Rms Error

Electro-mechanical disorders in cardiac function result in arrhythmias. Due to the non-stationary nature of these arrhythmias and, owing to lethality associated with certain type of arrhythmias, they are challenging to study. Most of the existing studies are limited in that they extract electrical activity from surface intracardiac electrical activity, either through the use of electrical or optical mapping. One way of studying current pathways inside and through biological tissues is by using Magnetic Resonance Imaging (MRI) based Low Frequency Current Density Imaging (LFCDI). For the first time CDI was used to study ex-vivo beating hearts in different cardiac states. It should be said that; this approach involves heavy logistical and procedural complexity, hence, it would be beneficial to adapt existing electrophysiological computer models to investigate and simulate current density maps specific to studying cardiac function. In achieving this, the proposed work presents an approach to model the current density maps in 3D and study the current distributions in different electrophysiological states of the heart. The structural and fiber orientation of the heart used in this study were extracted using MRI-based Diffusion Tensor Imaging. The monodomain and bidomain Aliev-Panfilov electrophysiological models were used for CDI modeling, and the results indicate that different states were distinguishable using range and correlation of simulated current density maps. The obtained results through modeling were corroborated with actual experimental CDI data from porcine hearts. Individually and comparatively, the experimental and simulation results for various states have the same trend in terms of variations (trend correlation coefficients ≥ 0.98) and state correlations (trend correlation coefficients ≥ 0.89). The results also show that the root mean square (RMS) error in average range ratios between bidomain CDI model results and real CDI data is 0.1972 and the RMS error in state correlations between bidomain CDI model results and real CDI data is 0.2833. These results indicate, as expected, the proposed bidomain model simulation of CDI corroborates well with experimental data and can serve as a valuable tool for studying lethal cardiac arrhythmias under different simulation conditions that are otherwise not possible or difficult in a real-world experimental setup.

scholarly journals Simulation models of current density imaging in studying cardiac states

2021 ◽  
Author(s):  
Mohammadali Beheshti
Keyword(s):  
Cardiac Function ◽  
Electrical Activity ◽  
Current Density ◽  
Diffusion Tensor ◽  
Model Simulation ◽  
Correlation Coefficients ◽  
Biological Tissues ◽  
Density Maps ◽  
Current Density Imaging ◽  
Rms Error

Electro-mechanical disorders in cardiac function result in arrhythmias. Due to the non-stationary nature of these arrhythmias and, owing to lethality associated with certain type of arrhythmias, they are challenging to study. Most of the existing studies are limited in that they extract electrical activity from surface intracardiac electrical activity, either through the use of electrical or optical mapping. One way of studying current pathways inside and through biological tissues is by using Magnetic Resonance Imaging (MRI) based Low Frequency Current Density Imaging (LFCDI). For the first time CDI was used to study ex-vivo beating hearts in different cardiac states. It should be said that; this approach involves heavy logistical and procedural complexity, hence, it would be beneficial to adapt existing electrophysiological computer models to investigate and simulate current density maps specific to studying cardiac function. In achieving this, the proposed work presents an approach to model the current density maps in 3D and study the current distributions in different electrophysiological states of the heart. The structural and fiber orientation of the heart used in this study were extracted using MRI-based Diffusion Tensor Imaging. The monodomain and bidomain Aliev-Panfilov electrophysiological models were used for CDI modeling, and the results indicate that different states were distinguishable using range and correlation of simulated current density maps. The obtained results through modeling were corroborated with actual experimental CDI data from porcine hearts. Individually and comparatively, the experimental and simulation results for various states have the same trend in terms of variations (trend correlation coefficients ≥ 0.98) and state correlations (trend correlation coefficients ≥ 0.89). The results also show that the root mean square (RMS) error in average range ratios between bidomain CDI model results and real CDI data is 0.1972 and the RMS error in state correlations between bidomain CDI model results and real CDI data is 0.2833. These results indicate, as expected, the proposed bidomain model simulation of CDI corroborates well with experimental data and can serve as a valuable tool for studying lethal cardiac arrhythmias under different simulation conditions that are otherwise not possible or difficult in a real-world experimental setup.

scholarly journals Relativity or aromaticity? A first-principles perspective of chemical shifts in osmabenzene and osmapentalene derivatives

2020 ◽  
Vol 22 (19) ◽  
pp. 10863-10869 ◽  
Author(s):  
Cina Foroutan-Nejad ◽  
Jan Vícha ◽  
Abhik Ghosh
Keyword(s):  
Current Density ◽  
First Principles ◽  
Chemical Shifts ◽  
Induced Current ◽  
Aromatic System ◽  
System P

The topology of the magnetically induced current density in osmabenzene suggests that the molecule is a novel type of Craig–Möbius aromatic system.

Spatial Correspondence Between Functional MRI (fMRI) Activations and Cortical Current Density Maps of Event-Related Potentials (ERP): A Study with Four Tasks

2008 ◽  
Vol 21 (2) ◽  
pp. 112-127 ◽  
Author(s):  
Ludovico Minati ◽  
Cristina Rosazza ◽  
Ileana Zucca ◽  
Ludovico D’Incerti ◽  
Vidmer Scaioli ◽  
...  
Keyword(s):  
Functional Mri ◽  
Current Density ◽  
Event Related Potentials ◽  
Spatial Correspondence ◽  
Density Maps ◽  
Related Potentials

Current density maps, magnetizability, and nuclear magnetic shielding tensors of bis-heteropentalenes. III. Thieno-thiophene isomers

2005 ◽  
Vol 103 (6-8) ◽  
pp. 789-801 ◽  
Author(s):  
I. García Cuesta ◽  
R. Soriano Jartín ◽  
A. Sánchez de Merás ◽  
P. Lazzeretti *
Keyword(s):  
Current Density ◽  
Magnetic Shielding ◽  
Density Maps ◽  
Shielding Tensors ◽  
Nuclear Magnetic Shielding Tensors ◽  
Nuclear Magnetic

Current density maps, magnetizability, and nuclear magnetic shielding tensors of bis-heteropentalenes. I. Di-hydro-pyrrolo–pyrrole isomers

2003 ◽  
Vol 119 (11) ◽  
pp. 5518-5526 ◽  
Author(s):  
I. Garcı́a Cuesta ◽  
R. Soriano Jartı́n ◽  
A. Sánchez de Merás ◽  
P. Lazzeretti
Keyword(s):  
Current Density ◽  
Magnetic Shielding ◽  
Density Maps ◽  
Shielding Tensors ◽  
Nuclear Magnetic Shielding Tensors ◽  
Nuclear Magnetic

scholarly journals Magnetically induced ring currents in metallocenothiaporphyrins

2021 ◽  
Author(s):  
Rashid R. Valiev ◽  
Theo Kurtén ◽  
Lenara Valiulina ◽  
Sergey Yu. Ketkov ◽  
Victor Cherepanov ◽  
...  
Keyword(s):  
Current Density ◽  
Triplet States ◽  
Induced Current ◽  
Susceptibility Tensor ◽  
Ring Currents ◽  
Singlet And Triplet States

The magnetically induced current-density susceptibility tensor (CDT) of the lowest singlet and triplet states of the metallocenothiaporphyrins, where the metal is V, Cr, Mn, Fe, Co, Ni, Mo, Tc, Ru,...

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