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    Plaque structure affects mechanical stress distribution within blood vessels

    , Article Proceedings of the IASTED International Conference on Biomedical Engineering, BioMed 2014 ; 2014 , pp. 239-243 Mohseni, M ; Mehboudi, N ; Abdollahi, M ; Shamloo, A ; Naghdabadi, R ; Sharif University of Technology
    Abstract
    The main goal of this study is to investigate the effects of plaque structure on its stress distribution. Rupture of plaque causes cerebrovascular diseases which lead to high mortality rates all over the world. Computers are powerful tools to understand the mechanism of plaque rupture. In this study, 3D fluid structure interaction simulation is constructed in ABAQUS 6.13 to clarify the relation between stress distribution of plaque and its structure. A model of common carotid artery with distributed stenosis was chosen for the simulation. To investigate the effects of plaque structure on stress distribution, thickness of fibrous cap and lipid core size were varied in the stenosis.... 

    Numerical simulations of cyclic behaviors in light alloys under isothermal and thermo-mechanical fatigue loadings

    , Article Materials and Design ; Vol. 56 , April , 2014 , pp. 245-253 ; ISSN: 02641275 Farrahi, G. H ; Shamloo, A ; Felfeli, M ; Azadi, M ; Sharif University of Technology
    Abstract
    In this article, numerical simulations of cyclic behaviors in light alloys are conducted under isothermal and thermo-mechanical fatigue loadings. For this purpose, an aluminum alloy (A356) which is widely used in cylinder heads and a magnesium alloy (AZ91) which can be applicable in cylinder heads are considered to study their stress-strain hysteresis loops. Two plasticity approaches including the Chaboche's hardening model and the Nagode's spring-slider model are applied to simulate cyclic behaviors. To validate obtained results, strain-controlled fatigue tests are performed under low cycle and thermo-mechanical fatigue loadings. Numerical results demonstrate a good agreement with... 

    Thickness as an important parameter in designing vascular grafts

    , Article 2014 21st Iranian Conference on Biomedical Engineering, ICBME 2014 ; Nov , 2014 , p. 40-43 Mohseni, M ; Shamloo, A ; Samani, S. A ; Dodel, M ; Sharif University of Technology
    Abstract
    The main goal of this study is to investigate the role of vascular graft thickness in wall stress gradient in anastomosis region. Atherosclerosis is a common heart disease causes high mortality rates every year. The gold standard treatment of atherosclerosis is replacing with autologous vein extracted from patient's body. Since proper autologous vein is limited, researchers have made efforts to achieve compliance engineered blood vessels. Mechanical stress has great effect on both smooth muscle cells and endothelial cells and it is considered as a stimulus in plaque formation. In this study, we evaluate the role of thickness in wall stress of anastomosis region. For this purpose, two... 

    Liquid-liquid equilibrium (LLE) data for ternary mixtures of {aliphatic+p-xylene+[EMpy][ESO 4]} at T=313.15K

    , Article Fluid Phase Equilibria ; Volume 332 , 2012 , Pages 48-54 ; 03783812 (ISSN) Kamankesh, A ; Vossoughi, M ; Shamloo, A ; Mirkhani, S. A ; Akbari, J ; Sharif University of Technology
    Elsevier  2012
    Abstract
    Liquid-liquid equilibrium (LLE) data for the ternary systems (heptane. +. p-xylene. +. 1-ethyl-3-methylpyridinium ethylsulfate) and (n-octane. +. p-xylene. +. 1-ethyl-3-methylpyridinium ethylsulfate) were measured at . T=. 313.15. K and atmospheric pressure. The selectivity and aromatic distribution coefficients, calculated from the equilibrium data, were used to determine if this ionic liquid can be used as a potential extracting solvent for the separation of p-xylene from heptane and n-octane. The consistency of tie-line data was ascertained by applying the Othmer-Tobias and Hand equations  

    Three dimensional modeling of axonal microtubules

    , Article 2014 21st Iranian Conference on Biomedical Engineering, ICBME 2014, 26 November 2014 through 28 November 2014 ; November , 2014 , Pages 298-302 ; 9781479974177 (ISBN) Manuchehrfar, F ; Shamloo, A ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2014
    Abstract
    Axon is a filament in neuronal system and axonal microtubules are bundles in axons. In axons, microtubules are coated with microtubule-associated protein tau, a natively unfolded profuse filamentous protein in the central nervous system. These proteins are responsible for the cross-linked structure of the axonal microtubule bundles. Through complimentary dimerization with other tau proteins, bridges are formed to nearby microtubules to create bundles. The transverse reinforcement of microtubules by cross-linking to the cytoskeleton has been shown to enhance their ability to bear compressive loads. Though microtubules are conventionally regarded as bearing compressive loads, in certain... 

    Thickness as an important parameter in designing vascular grafts

    , Article 2014 21st Iranian Conference on Biomedical Engineering, ICBME 2014, 26 November 2014 through 28 November 2014 ; November , 2014 , Pages 40-43 ; 9781479974177 (ISBN) Mohseni, M ; Shamloo, A ; Samani, S. A ; Dodel, M ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2014
    Abstract
    The main goal of this study is to investigate the role of vascular graft thickness in wall stress gradient in anastomosis region. Atherosclerosis is a common heart disease causes high mortality rates every year. The gold standard treatment of atherosclerosis is replacing with autologous vein extracted from patient's body. Since proper autologous vein is limited, researchers have made efforts to achieve compliance engineered blood vessels. Mechanical stress has great effect on both smooth muscle cells and endothelial cells and it is considered as a stimulus in plaque formation. In this study, we evaluate the role of thickness in wall stress of anastomosis region. For this purpose, two... 

    A model for cell density effect on stress fiber alignment and collective directional migration

    , Article Physical Biology ; Volume 12, Issue 6 , 2015 ; 14783967 (ISSN) Abeddoust, M ; Shamloo, A ; Sharif University of Technology
    2015
    Abstract
    In this study, numerical simulation of collective cell migration is presented in order to mimic the group migration of endothelial cells subjected to the concentration gradients of a biochemical factor. The developed 2D model incorporates basic elements of the cell, including both the cell membrane and the cell cytoskeleton, based on a viscoelastic cell mechanic model. Various cell processes - including cell random walk, cell-cell interactions, cell chemotaxis, and cellular cytoskeleton rearrangements - are considered and analyzed in our developed model. After validating the model by using available experimental data, the model is used to investigate various important parameters during... 

    Toward epileptic brain region detection based on magnetic nanoparticle patterning

    , Article Sensors (Switzerland) ; Volume 15, Issue 9 , September , 2015 , Pages 24409-24427 ; 14248220 (ISSN) Pedram, M. Z ; Shamloo, A ; Alasty, A ; Ghafar Zadeh, E ; Sharif University of Technology
    MDPI AG  2015
    Abstract
    Resection of the epilepsy foci is the best treatment for more than 15% of epileptic patients or 50% of patients who are refractory to all forms of medical treatment. Accurate mapping of the locations of epileptic neuronal networks can result in the complete resection of epileptic foci. Even though currently electroencephalography is the best technique for mapping the epileptic focus, it cannot define the boundary of epilepsy that accurately. Herein we put forward a new accurate brain mapping technique using superparamagnetic nanoparticles (SPMNs). The main hypothesis in this new approach is the creation of super-paramagnetic aggregates in the epileptic foci due to high electrical and... 

    High throughput blood plasma separation using a passive PMMA microfluidic device

    , Article Microsystem Technologies ; 2015 ; 09467076 (ISSN) Shamsi, A ; Shamloo, A ; Mohammadaliha, N ; Hajghassem, H ; Mehrabadi, J. F ; Bazzaz, M ; Sharif University of Technology
    Springer Verlag  2015
    Abstract
    Since plasma is rich in many biomarkers used in clinical diagnostic experiments, microscale blood plasma separation is a primitive step in most of microfluidic analytical chips. In this paper, a passive microfluidic device for on-chip blood plasma separation based on Zweifach–Fung effect and plasma skimming was designed and fabricated by hot embossing of microchannels on a PMMA substrate and thermal bonding process. Human blood was diluted in various times and injected into the device. The main novelty of the proposed microfluidic device is the design of diffuser-shaped daughter channels. Our results demonstrated that this design exerted a considerable positive influence on the separation... 

    Steered molecular dynamic simulation approaches for computing the blood brain barrier (BBB) diffusion coefficient

    , Article IFMBE Proceedings ; Volume 51 , 2015 , Pages 1699-1703 ; 16800737 (ISSN) ; 9783319193878 (ISBN) Pedram, M. Z ; Shamloo, A ; Alasti, A ; Zadeh, E. G ; Jaffray D. A ; Sharif University of Technology
    Springer Verlag  2015
    Abstract
    In the recent years a great attention of research deals with different physical and biological aspects of the BBB structure, a robust shield that separates the blood and brain, a recent research held by the authors of this paper has focused on figuring out computing the diffusion coefficient of endothelial cell membrane. In this study, the major efforts have been concentrated on calculating a standardized measure for the amount of permeability and diffusion of this barrier. As a result, this work is dedicated to molecular dynamics (MD) simulation of calculating the interaction force between nano-particle and BBB membrane. data is recorded by using steered molecular dynamics simulation and... 

    Superparamagnetic nanoparticles for epilepsy detection

    , Article World Congress on Medical Physics and Biomedical Engineering, 2015, 7 June 2015 through 12 June 2015 ; Volume 51 , June , 2015 , Pages 1237-1240 ; 16800737 (ISSN) ; 9783319193878 (ISBN) Pedram, M. Z ; Shamloo, A ; Alasty, A ; Ghafar Zadeh, E ; Jaffray D. A ; Sharif University of Technology
    Springer Verlag  2015
    Abstract
    Epilepsy is the most common neurological disorder that is known with uncontrolled seizure. Around 30% of patients with epilepsy resist to all forms of medical treatments and therefore, the removal of epileptic brain tissue is the only solution to get these patients free from chronical seizures. The precise detection of an epileptic zone is key to its treatment. In this paper, we propose a method of epilepsy detection using brain magnetic field. The possibility of superparamagnetic nanoparticle (SPMN) as sensors for the detection of the epileptic area inside the brain is investigated. The aggregation of nanoparticles in the weak magnetic field of epileptic brain is modeled using potential... 

    A computational model for estimation of mechanical parameters in chemotactic endothelial cells

    , Article Scientia Iranica ; Volume 23, Issue 1 , 2016 , Pages 260-267 ; 10263098 (ISSN) Kiyoumarsioskouei, A ; Shamloo, A ; Azimi, S ; Abeddoust, M ; Saidi, M.S ; Sharif University of Technology
    Sharif University of Technology 
    Abstract
    A cell migration numerical simulation is presented to mimic the motility of endothelial cells subjected to the concentration gradients of a Forebrain embryoniccortical neuron Conditioned Medium (CM). This factor was previously shflown to induce the directional chemotaxis of endothelial cells with an over-expressed G protein coupled receptor 124 (GPR 124). A cell simulator program incorporates basic elements of the cell cytoskeleton, including membrane, nucleus and cytoskeleton. The developed 2D cell model is capable of responding to concentration gradients of biochemical factors by changing the cytoskeleton arrangement. Random walk force, cell drag force and cell inertial effects are also... 

    The effect of rippled graphene sheet roughness on the adhesive characteristics of a collagen-graphene system

    , Article International Journal of Adhesion and Adhesives ; Volume 64 , 2016 , Pages 9-14 ; 01437496 (ISSN) Heidari, H ; Shamloo, A ; Sharif University of Technology
    Elsevier Ltd 
    Abstract
    A great amount of effort has been made in order to reach a more precise understanding of the adhesion phenomenon that happens as a vital component of several biological systems. Therefore, a firm understanding of the important factors that influence this phenomenon is of special importance in triggering the adhesive characteristics of different biological, bio-inspired and synthetic materials in fields such as tissue engineering. In this study the adhesive characteristics of a multi-material system consisting of the frequently used synthetic material, graphene, in the form of armchair-configuration sheets, and an important biological filament which is type 1 Collagen consisting of 3 alpha... 

    Modeling Paramecium swimming in a capillary tube

    , Article Scientia Iranica ; Volume 23, Issue 2 , 2016 , Pages 658-667 ; 10263098 (ISSN) Sarvestani, A. N ; Shamloo, A ; Ahmadian, M. T ; Sharif University of Technology
    Sharif University of Technology 
    Abstract
    In certain types of biomimetic surgery systems, micro robots inspired by Paramecium are designed to swim in a capillary tube for gaining access to internal organs with minimal invasion. Gaining insight into the mechanics of Paramecium swimming in a capillary tube is vital for optimizing the design of such systems. There are two approaches to modeling the physics of micro swimming. In the envelope approach, which is widely accepted by researchers, Paramecium is approximated as a sphere, self-propelled by tangential and normal surface distortions. However, not only is this approach incapable of considering the specific geometry of Paramecium, but it also neglects short range hydrodynamic... 

    Dual improvement of DNA-directed antibody immobilization utilizing magnetic fishing and a polyamine coated surface

    , Article RSC Advances ; Volume 6, Issue 112 , 2016 , Pages 111210-111216 ; 20462069 (ISSN) Esmaeili, E ; Soleimani, M ; Shamloo, A ; Mahmoudifard, M ; Vossoughi, M ; Sharif University of Technology
    Royal Society of Chemistry  2016
    Abstract
    The present study is aimed at the development of a novel approach based on the magnetic improvement of DNA-directed antibody immobilization to prepare a highly efficient sensing platform. Magnetic nanoparticle substrates with high surface area capture the dual DNA-conjugated antibodies in a solution. This allows overcoming the typical mass transport limitation of the surface-based antibody immobilization. Antibody-magnetic nanoparticle conjugation is based on a robust hybridization between a DNA tether (attached to the antibody) and its complementary sequence (immobilized on the nanoparticle). Conventional antibody immobilization for the detection of proteins is often insignificant for the... 

    High throughput blood plasma separation using a passive PMMA microfluidic device

    , Article Microsystem Technologies ; Volume 22, Issue 10 , 2016 , Pages 2447-2454 ; 09467076 (ISSN) Shamsi, A ; Shamloo, A ; Mohammadaliha, N ; Hajghassem, H ; Fallah Mehrabadi, J ; Bazzaz, M ; Sharif University of Technology
    Springer Verlag  2016
    Abstract
    Since plasma is rich in many biomarkers used in clinical diagnostic experiments, microscale blood plasma separation is a primitive step in most of microfluidic analytical chips. In this paper, a passive microfluidic device for on-chip blood plasma separation based on Zweifach–Fung effect and plasma skimming was designed and fabricated by hot embossing of microchannels on a PMMA substrate and thermal bonding process. Human blood was diluted in various times and injected into the device. The main novelty of the proposed microfluidic device is the design of diffuser-shaped daughter channels. Our results demonstrated that this design exerted a considerable positive influence on the separation... 

    Antimicrobial wound dressing containing silver sulfadiazine with high biocompatibility: In vitro study

    , Article Artificial Organs ; Volume 40, Issue 8 , 2016 , Pages 765-773 ; 0160564X (ISSN) Mohseni, M ; Shamloo, A ; Aghababaei, Z ; Vossoughi, M ; Moravvej, H ; Sharif University of Technology
    Blackwell Publishing Inc 
    Abstract
    Many patients all over the world suffer from acute wounds caused by traumas or burns. In most crucial cases, skin regeneration cannot be promoted spontaneously, and skin grafts are applied as the main treatment. However, this therapy has some drawbacks which motivate researchers to develop wound dressings. In this study, electrospun mats consisting of polycaprolactone (PCL) and polyvinyl alcohol (PVA) incorporated with silver sulfadiazine (SSD) are proposed to be used as antimicrobial wound dressings with the capability of cell seeding. Various amounts of SSD were loaded into PVA nanofibers, and the effects of SSD particles on the morphological characteristics of nanofibers, mechanical... 

    Optimal magnetic field for crossing super-para-magnetic nanoparticles through the Brain Blood Barrier: A computational approach

    , Article Biosensors ; Volume 6, Issue 2 , 2016 ; 20796374 (ISSN) Pedram, M. Z ; Shamloo, A ; Alasty, A ; Ghafar Zadeh, E ; Sharif University of Technology
    MDPI AG  2016
    Abstract
    This paper scrutinizes the magnetic field effect to deliver the superparamagnetic nanoparticles (SPMNs) through the Blood Brain Barrier (BBB). Herein we study the interaction between the nanoparticle (NP) and BBB membrane using Molecular Dynamic (MD) techniques. The MD model is used to enhance our understanding of the dynamic behavior of SPMNs crossing the endothelial cells in the presence of a gradient magnetic field. Actuation of NPs under weak magnetic field offers the great advantage of a non-invasive drug delivery without the risk of causing injury to the brain. Furthermore, a weak magnetic portable stimulator can be developed using low complexity prototyping techniques. Based on MD... 

    Simulation of Paramecium Chemotaxis Exposed to Calcium Gradients

    , Article Cell Biochemistry and Biophysics ; Volume 74, Issue 2 , 2016 , Pages 241-252 ; 10859195 (ISSN) Nematollahi Sarvestani, A ; Shamloo, A ; Ahmadian, M. T ; Sharif University of Technology
    Humana Press Inc  2016
    Abstract
    Paramecium or other ciliates have the potential to be utilized for minimally invasive surgery systems, making internal body organs accessible. Paramecium shows interesting responses to changes in the concentration of specific ions such as K+, Mg2+, and Ca2+ in the ambient fluid. Some specific responses are observed as, changes in beat pattern of cilia and swimming toward or apart from the ion source. Therefore developing a model for chemotactic motility of small organisms is necessary in order to control the directional movements of these microorganisms before testing them. In this article, we have developed a numerical model, investigating the effects of Ca2+ on swimming trajectory of... 

    Droplet-based flows in serpentine microchannels: chemical reactions and secondary flows

    , Article International Journal of Multiphase Flow ; Volume 97 , 2017 , Pages 186-196 ; 03019322 (ISSN) Madadelahi, M ; Shamloo, A ; Sharif University of Technology
    Abstract
    Mixing is an essential operation in many microfluidic devices. Droplet-based micromixers utilize droplets for mixing enhancement. In the present study, a novel three-dimensional simulation is conducted which has the ability to capture not only the mixing process, but also the chemical reactions inside liquid droplets. This two-phase model is used for simulating the reacting flow inside a serpentine microchannel and explores the effects of droplet size and reaction rate on the production and consumption of species in droplets. It is observed that the chemical reaction in each droplet, begins from its front area. Furthermore, it is shown that the production of species does not depend on water...