A simple technique for morphological measurement of cerebral arterial circle variations using public domain software (Osiris)

Saeed Ansari,Majid Dadmehr,Behzad Eftekhar,Douglas J. McConnell,Sarah Ganji,Hassan Azari,Shahab Kamali-Ardakani,Brian L. Hoh,J. Mocco 대한해부학회 2011 Anatomy & Cell Biology Vol.44 No.4

This article describes a straightforward method to measure the dimensions and identify morphological variations in the cerebral arterial circle using the general-purpose software program Osiris. This user-friendly and portable program displays, manipulates, and analyzes medical digital images, and it has the capability to determine morphometric properties of selected blood vessels (or other anatomical structures) in humans and animals. To ascertain morphometric variations in the cerebral arterial circle, 132 brains of recently deceased fetuses, infants, and adults were dissected. The dissection procedure was first digitized, and then the dimensions were measured with Osiris software. Measurements of each vessel’s length and external diameters were used to identify and classify morphological variations in the cerebral arterial circle. The most commonly observed anatomical variations were uni- and bilateral hypoplasia of the posterior communicating artery. This study demonstrates that public domain soft ware can be used to measure and classify cerebral arterial circle vessels. This method could be extended to examine other anatomical regions or to study other animals. Additionally, knowledge of variations within the circle could be applied clinically to enhance diagnostic and treatment specificity.

A new approach to tailoring the separation characteristics of polyethersulfone nanofiltration membranes by 8-hydroxyquinoline functionalized Fe3O4 nanoparticles

Saeed Ansari,Abdolreza Moghadassi,Sayed Mohsen Hosseini 한국화학공학회 2020 Korean Journal of Chemical Engineering Vol.37 No.11

8-Hydroxyquinoline (8-HQ) was used for modification of Fe3O4 nanoparticles (NPs) and preparation of polyethersulfone (PES)-based mixed matrix membranes (MMMs) by phase inversion process. The synthesized nanoparticles were characterized by Fourier transform infrared spectroscopy (FTIR), Energy dispersive x-ray spectroscopy (EDX), and Field emission scanning electron microscopy (FESEM). The effect of different concentrations of 8- HQ/Fe3O4 NPs into the PES as membrane matrix was investigated by FESEM and atomic force microscopy (AFM). The performance of prepared membranes was evaluated by the water contact angle, pure water flux (PWF), porosity, means pore size, and salt rejection. Bovine serum albumin (BSA) solution was used to investigate the antifouling properties of fabricated membranes. The results showed a decreasing water contact angle from 68.1o for the pristine membrane to 38.3o for M5 at 0.5 wt% 8-HQ/Fe3O4 NPs. The PWF enhanced for all mixed matrix membranes compared with the pristine membrane. The highest PWF (21.5 L/m2h) was measured for M4 at 0.2wt% NPs, Wwhile it was 7.1 L/m2h for pristine membrane. Salt rejection improved from 58.55% in M1 (pristine membrane) to 96% in M4 (at 0.2 wt% of 8-HQ/Fe3O4 NPs). Also, the modified membranes showed suitable antifouling property.

Finite element modeling of the vibrational behavior of multi-walled nested silicon-carbide and carbon nanotubes

Abed Nikkar,Saeed Rouhi,Reza Ansari 국제구조공학회 2017 Structural Engineering and Mechanics, An Int'l Jou Vol.64 No.3

This study concerns the vibrational behavior of multi-walled nested silicon-carbide and carbon nanotubes using the finite element method. The beam elements are used to model the carbon-carbon and silicon-carbon bonds. Besides, spring elements are employed to simulate the van der Waals interactions between walls. The effects of nanotube arrangement, number of walls, geometrical parameters and boundary conditions on the frequencies of nested silicon-carbide and carbon nanotubes are investigated. It is shown that the double-walled nanotubes have larger frequencies than triple-walled nanotubes. Besides, replacing silicon carbide layers with carbon layers leads to increasing the frequencies of nested silicon-carbide and carbon nanotubes. Comparing the first ten mode shapes of nested nanotubes, it is observed that the mode shapes of armchair and zigzag nanotubes are almost the same.

BEST PROXIMITY POINTS OF GENERALIZED CYCLIC WEAK (F,ψ,φ)-CONTRACTIONS IN ORDERED METRIC SPACES

Arslan Hojat Ansari,Jamnian Nantadilok,Mohammad Saeed Khan 경남대학교 기초과학연구소 2020 Nonlinear Functional Analysis and Applications Vol.25 No.1

The purpose of this paper is to introduce a new generalized cyclic weak (F, ψ, φ)- contraction based on the generalized weak φ -contraction which is proposed in [6], where F is a C-class function. Moreover, we obtain a corresponding best proximity point theorem for this cyclic mapping under certain condition. Our results obtained in this paper improve and extend previous known results in [6], as well as other results for cyclic contractions in the existing literature.

Time Division Multiplexing based Test Access for Stacked ICs

Muhammad Adil Ansari,Umair Saeed Solnagi,Jinuk Kim,Ahsin Murtaza Bughio,Sungju Park 대한전자공학회 2019 Journal of semiconductor technology and science Vol.19 No.1

The test cost and complexity of stacked ICs (SICs) are higher than those of 2D-ICs because an SIC is tested at more stages before shipping. The existing test access architectures and their optimization techniques for SICs underutilize the tester-channel frequency because the test data is shifted at low scan-shift frequency due to test power constrain. Moreover, the wafer-level test frequency is constrained by limited probe-pin to pad contact current; however, the package-level test can be performed at a higher frequency yet lower than the tester-channel frequency offered by the testers. Therefore, we present a time-multiplexed test access architecture for SICs that leverages the tester-channel frequency at both the wafer-level and package-level tests. Unlike exiting architectures, the proposed architecture does not require the knowledge of the number of dies to be stacked and the hierarchical tier of each die. The proposed architecture is discussed for SICs based on IEEE standards 1149.1 and 1500. The experimental results with a synthetic SIC, constructed with ITC’02 benchmark SoCs, show significant reduction in the test time. Furthermore, the analyses based on the test frequency limits and the number of stacked dies show that the proposed architecture scales well with increasing frequency limits and the number of stacked dies.

Hemispheric Differences in Ischemic Stroke: Is Left-Hemisphere Stroke More Common?

Vishnumurthy Shushrutha Hedna,Aakash N Bodhit,Saeed Ansari,Adam D Falchook,Latha Stead,Kenneth M Heilman,,Michael F Waters 대한신경과학회 2013 Journal of Clinical Neurology Vol.9 No.2

Background and Purpose Understanding the mechanisms underlying stroke can aid the development of therapies and improve the final outcome. The purposes of this study were to establish whether there are characteristic mechanistic differences in the frequency, severity, functional outcome, and mortality between left- and right-hemisphere ischemic stroke and, given the velocity differences in the carotid circulation and direct branching of the left common carotid artery from the aorta, whether large-vessel ischemia (including cardioembolism) is more common in the territory of the left middle cerebral artery. Methods Trial cohorts were combined into a data set of 476 samples. Using Trial of Org 10172 in Acute Stroke Treatment criteria, ischemic strokes in a total 317 patients were included in the analysis. Hemorrhagic stroke, stroke of undetermined etiology, cryptogenic stroke, and bilateral ischemic strokes were excluded. Laterality and vascular distribution were correlated with outcomes using a logistic regression model. The etiologies of the large-vessel strokes were atherosclerosis and cardioembolism. Results The overall event frequency, mortality, National Institutes of Health Stroke Scale (NIHSS)score, Glasgow Coma Scale score, and rate of mechanical thrombectomy interventions differed significantly between the hemispheres. Left-hemispheric strokes (54%) were more common than right-hemispheric strokes (46%; p=0.0073), and had higher admission NIHSS scores (p=0.011),increased mortality (p=0.0339), and higher endovascular intervention rates (p≤0.0001). ischemic strokes were more frequent in the distribution of the left middle cerebral artery (122 vs. 97;p=0.0003) due to the higher incidence of large-vessel ischemic stroke in this area (p=0.0011). Conclusions Left-hemispheric ischemic strokes appear to be more frequent and often have a worse outcome than their right-hemispheric counterparts. The incidence of large-vessel ischemic strokes is higher in the left middle cerebral artery distribution, contributing to these hemispheric differences. The hemispheric differences exhibit a nonsignificant trend when strokes in the middle cerebral artery distribution are excluded from the analysis.