Is the asymmetry between the vertebral arteries related to the cerebral dominance?

Abstract Objective Lately, morphological parameters of the surrounding vasculature aside from aneurysm size, specific for the aneurysm location, e.g., posterior cerebral artery angle for basilar artery tip aneurysms, could be identified to correlate with the risk of rupture. We examined further image-based morphological parameters of the aneurysm surrounding vasculature that could correlate with the growth or the risk of rupture of basilar artery tip aneurysms. Methods Data from 83 patients with basilar tip aneurysms (27 not ruptured; 56 ruptured) and 100 control patients were assessed (50 without aneurysms and 50 with aneurysms of the anterior circle of Willis). Anatomical parameters of the aneurysms were assessed and analyzed, as well as of the surrounding vasculature, namely the asymmetry of P1 and the vertebral arteries. Results Patients with basilar tip aneurysm showed no significant increase in P1 or vertebral artery asymmetry compared with the control patients or patients with aneurysms of the anterior circulation, neither was there a significant difference in asymmetry between cases with ruptured and unruptured aneurysms. Furthermore, we observed no significant correlations between P1 asymmetry and the aneurysm size or number of lobuli in the aneurysms. Conclusion We observed no significant difference in aneurysm size, rupture, or lobulation associated with P1 or vertebral artery (surrounding vasculature) asymmetry. Therefore, the asymmetry of the surrounding vessels does not seem to be a promising morphological parameter for the evaluation of probability of rupture and growth in basilar tip aneurysms in future studies.

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Time-resolved, contrast-enhanced 3D MR angiography in the subclavian steal effect

VASA ◽

10.1024/0301-1526/a000009 ◽

2010 ◽

Vol 39 (1) ◽

pp. 85-93 ◽

Cited By ~ 1

Author(s):

Schubert

Keyword(s):

Mr Angiography ◽

Time Resolved ◽

Time To Peak ◽

Vertebral Arteries ◽

Subclavian Steal ◽

Cerebrovascular Events ◽

Graphic Analysis ◽

Contrast Enhanced ◽

Hemodynamic Information ◽

Supraaortic Vessels

The subclavian steal effect indicates atherosclerotic disease of the supraaortic vessels but rarely causes cerebrovascular events in itself. Noninvasive imaging providing detailed anatomic as well as hemodynamic information would therefore be desirable. From a group of 25 consecutive patients referred for MR angiography, four with absent or highly attenuated signal in one of the vertebral arteries on 3D multislab time-of-flight MR angiography were selected to undergo 3D time-resolved contrast-enhanced MR angiography. The time-resolved 3D contrast series (source images and MIPs) were evaluated visually and by graphic analysis of time-intensity curves derived from the respective V1 and V3 segments of both vertebral arteries on the source images. In two cases with high-grade proximal left subclavian stenosis, time-resolved 3D ce-MRA was able to visualise retrograde contrast filling of the left VA. There was a marked delay in time-to-peak between the left and right V1 segments in one case and a shallower slope of enhancement in another. In the other two cases, there was complete or collateralised segmental occlusion of the VAs.

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Cued language switching in sentence reading: Exploring the asymmetry of the cost

PsycEXTRA Dataset ◽

10.1037/e512592013-705 ◽

2011 ◽

Author(s):

A. Ibanez ◽

L. Morales ◽

M. T. Bajo

Keyword(s):

Language Switching ◽

Sentence Reading ◽

The Asymmetry ◽

The Cost

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Social Connection, the Asymmetry of Similarity and Intergroup Relations

PsycEXTRA Dataset ◽

10.1037/e521512014-072 ◽

2012 ◽

Author(s):

Daniel A. Nadolny ◽

David Cwir ◽

Steven J. Spencer

Keyword(s):

Intergroup Relations ◽

Social Connection ◽

The Asymmetry

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Factors determining the observed values of the asymmetry coefficients of light fluxes in the atmosphere in the near-IR region

Оптика атмосферы и океана ◽

10.15372/aoo20180508 ◽

2018 ◽

Keyword(s):

Near Ir ◽

The Asymmetry

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EFFECT OF CELLULAR MEMBRANE RESISTIVITY INHOMOGENEITY ON THE THERMAL NOISE-LIMIT

JOURNAL OF ADVANCES IN PHYSICS ◽

10.24297/jap.v11i3.6859 ◽

2015 ◽

Vol 11 (3) ◽

pp. 3171-3183

Author(s):

Gyula Vincze

Keyword(s):

Field Strength ◽

Thermal Noise ◽

Cellular Membrane ◽

Thermal Limit ◽

Low Frequencies ◽

Membrane Resistivity ◽

Noise Limit ◽

The Asymmetry ◽

Characteristic Field

Our objective is to generalize the Weaver-Astumian (WA) and Kaune (KA) models of thermal noise limit to the case ofcellular membrane resistivity asymmetry. The asymmetry of resistivity causes different effects in the two models. In the KAmodel, asymmetry decreases the characteristic field strength of the thermal limit over and increases it below the breakingfrequency (10ï· ï€½ï´ mï€), while asymmetry decreases the spectral field strength of the thermal noise limit at all frequencies.We show that asymmetry does not change the character of the models, showing the absence of thermal noise limit at highand low frequencies in WA and KA models, respectively.

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Computational Investigation of the Asymmetry in Photosynthetic Reaction Center Models from First Principles

10.26434/chemrxiv.11980119.v1 ◽

2020 ◽

Author(s):

Denis Artiukhin ◽

Patrick Eschenbach ◽

Johannes Neugebauer

Keyword(s):

Spin Density ◽

Reaction Center ◽

Density Functional ◽

Photosynthetic Reaction Center ◽

Chem Phys ◽

Molecular Structures ◽

Error Characteristic ◽

Molecular Systems ◽

Density Distributions ◽

The Asymmetry

We present a computational analysis of the asymmetry in reaction center models of photosystem I, photosystem II, and bacteria from Synechococcus elongatus, Thermococcus vulcanus, and Rhodobacter sphaeroides, respectively. The recently developed FDE-diab methodology [J. Chem. Phys., 148 (2018), 214104] allowed us to effectively avoid the spin-density overdelocalization error characteristic for standard Kohn–Sham Density Functional Theory and to reliably calculate spin-density distributions and electronic couplings for a number of molecular systems ranging from dimeric models in vacuum to large protein including up to about 2000 atoms. The calculated spin densities showed a good agreement with available experimental results and were used to validate reaction center models reported in the literature. We demonstrated that the applied theoretical approach is very sensitive to changes in molecular structures and relative orientation of molecules. This makes FDE-diab a valuable tool for electronic structure calculations of large photosynthetic models effectively complementing the existing experimental techniques.

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