Geometric parameters on MRA source images to differentiate small Proximal Posterior communicating artery aneurysms from Infundibular dilation

2021 ◽  
Author(s):  
Yun Ji Kim ◽  
Dae Young Yoon ◽  
Eun Soo Kim ◽  
Eun Joo Yun ◽  
Hong Jun Jeon ◽  
...  
Keyword(s):  
Geometric Parameters ◽  
Posterior Communicating Artery

Lectin-Induced RBC Agglutination: Chemical vs. Cryofixation

1980 ◽  
Vol 38 ◽  
pp. 664-665
Author(s):  
Dean A. Handley ◽  
Lanping A. Sung ◽  
Shu Chien
Keyword(s):  
Lectin Binding ◽  
Freeze Substitution ◽  
Electrostatic Charge ◽  
Geometric Parameters ◽  
Comparative Approach ◽  
Chemical Fixation ◽  
Cell Surfaces ◽  
Minimal Cell ◽  
Membrane Stiffness ◽  
Cell Contour

RBC agglutination by lectins represents an interactive balance between the attractive (bridging) force due to lectin binding on cell surfaces and disaggregating forces, such as membrane stiffness and electrostatic charge repulsion (1). During agglutination, critical geometric parameters of cell contour and intercellular distance reflect the magnitude of these interactive forces and the size of the bridging macromolecule (2). Valid ultrastructural measurements of these geometric parameters from agglutinated RBC's require preservation with minimal cell distortion. As chemical fixation may adversely influence RBC geometric properties (3), we used chemical fixation and cryofixation (rapid freezing followed by freeze-substitution) as a comparative approach to examine these parameters from RBC agglutinated with Ulex I lectin.

Evaluation of the accuracy of reconstruction of the electrophysical and geometric parameters of multilayer dielectric coatings by the multi-frequency radio wave method of a slow surface electromagnetic waves

2020 ◽  
pp. 51-58
Author(s):  
Aleksandr I. Kazmin ◽  
Pavel A. Fedjunin
Keyword(s):  
Radio Wave ◽  
Noise Level ◽  
Electromagnetic Waves ◽  
Dielectric Materials ◽  
Geometric Parameters ◽  
Experimental Investigations ◽  
Wave Method ◽  
Dielectric Coatings ◽  
Surface Electromagnetic Waves ◽  
Multilayer Dielectric

One of the most important diagnostic problems multilayer dielectric materials and coatings is the development of methods for quantitative interpretation of the checkout results their electrophysical and geometric parameters. The results of a study of the potential informativeness of the multi-frequency radio wave method of surface electromagnetic waves during reconstruction of the electrophysical and geometric parameters of multilayer dielectric coatings are presented. The simulation model is presented that makes it possible to evaluate of the accuracy of reconstruction of the electrophysical and geometric parameters of multilayer dielectric coatings. The model takes into account the values of the electrophysical and geometric parameters of the coating, the noise level in the measurement data and the measurement bandwidth. The results of simulation and experimental investigations of reconstruction of the structure of relative permittivitties and thicknesses of single-layer and double-layer dielectric coatings with different thicknesses, with different values of the standard deviation (RMS) of the noise level in the measured attenuation coefficients of the surface slow electromagnetic wave are presented. Coatings based on the following materials were investigated: polymethyl methacrylate, F-4D PTFE, RO3010. The accuracy of reconstruction of the electrophysical parameters of the layers decreases with an increase in the number of evaluated parameters and an increase in the noise level. The accuracy of the estimates of the electrophysical parameters of the layers also decreases with a decrease in their relative permittivity and thickness. The results of experimental studies confirm the adequacy of the developed simulation model. The presented model allows for a specific measuring complex that implements the multi-frequency radio wave method of surface electromagnetic waves, to quantify the potential possibilities for the accuracy of reconstruction of the electrophysical and geometric parameters of multilayer dielectric materials and coatings. Experimental investigations and simulation results of a multilayer dielectric coating demonstrated the theoretical capabilities gained relative error permittivity and thickness of the individual layers with relative error not greater than 10 %, with a measurement bandwidth of 1 GHz and RMS of noise level 0,003–0,004.

CT and Angiographic Analysis of Posterior Communicating Artery Aneurysms: What Factors Influence the Amount of Subarachnoid Blood?

1998 ◽  
Vol 39 (3) ◽  
pp. 441
Author(s):  
Young Min Kim ◽  
Kun Sik Jung ◽  
Myung Ho Rho ◽  
Pil Youb Choi ◽  
Young Soon Sung ◽  
...  
Keyword(s):  
Posterior Communicating Artery ◽  
Subarachnoid Blood

Analysis of micro-geometric parameters of cut surfaces

2013 ◽  
Vol 8 (2) ◽  
pp. 55-66 ◽  
Author(s):  
Georgina Tóth ◽  
Ágota Drégelyi-Kiss ◽  
Béla Palásti-Kovács
Keyword(s):  
Geometric Parameters

Multiple Cerebral Aneurysm - Case Report

2014 ◽  
Vol 21 (3) ◽  
pp. 279-282 ◽  
Author(s):  
C. Kakucs ◽  
I. St. Florian
Keyword(s):  
Case Report ◽  
Carotid Artery ◽  
Internal Carotid Artery ◽  
Ct Scan ◽  
Cerebral Aneurysm ◽  
Internal Carotid ◽  
Neurological Status ◽  
Posterior Communicating Artery ◽  
Nuchal Rigidity ◽  
Angio Ct

Abstract This 41-years-old female presented with somnolence, confusion and nuchal rigidity. Preoperative angio-CT scan showed two aneurysm located on both internal carotid artery (ICA) at the site of posterior communicating artery (PComA). During surgery we discovered another dilatation on the origin of left ophtalmic artery that proves to be an infundibullum. We clipped the two communicating posterior aneurysm from the left side and the ophtalmic infundibullum was wrapped. Seven days after surgery the neurological status was improved and she was transferred to the Neurological department.

EFFECT OF GEOMETRIC PARAMETERS ON SEISMIC PERFORMANCE OF RC CHIMNEYS

2019 ◽  
Vol 9 (2) ◽  
pp. 46
Author(s):  
PATEL S. ISHA ◽  
MOHAN RAO B. D. V. CHANDRA ◽  
◽  
Keyword(s):  
Seismic Performance ◽  
Geometric Parameters
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