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    Volume and concentration dosing in picolitres using a two-channel microfluidic AFM cantilever

    , Article Nanoscale ; Volume 12, Issue 18 , 2020 , Pages 10292-10305 Verlinden, E. J ; Madadelahi, M ; Sarajlic, E ; Shamloo, A ; Engel, A. H ; Staufer, U ; Ghatkesar, M. K ; Sharif University of Technology
    NLM (Medline)  2020
    Abstract
    We introduce a two-channel microfluidic atomic force microscopy (AFM) cantilever that combines the nanomechanical sensing functionality of an AFM cantilever with the ability to manipulate fluids of picolitres or smaller volumes through nanoscale apertures near the cantilever tip. Each channel is connected to a separate fluid reservoir, which can be independently controlled by pressure. Various systematic experiments with fluorescent liquids were done by either injecting the liquids from the on-chip reservoir or aspirating directly through the nanoscale apertures at the tip. A flow rate analysis of volume dosing, aspiration and concentration dosing inside the liquid medium was performed. To... 

    Utilization of molecular dynamics simulation coupled with experimental assays to optimize biocompatibility of an electrospun PCL/PVA scaffold

    , Article PLoS ONE ; Volume 12, Issue 1 , 2017 ; 19326203 (ISSN) Sarmadi, M ; Shamloo, A ; Mohseni, M ; Sharif University of Technology
    Public Library of Science  2017
    Abstract
    The main focus of this study is to address the possibility of using molecular dynamics (MD) simulation, as a computational framework, coupled with experimental assays, to optimize composite structures of a particular electrospun scaffold. To this aim, first, MD simulations were performed to obtain an initial theoretical insight into the capability of heterogeneous surfaces for protein adsorption. The surfaces were composed of six different blends of PVA (polyvinyl alcohol) and PCL (polycaprolactone) with completely unlike hydrophobicity. Next, MTT assay was performed on the electrospun scaffolds made from the same percentages of polymers as in MD models to gain an understanding of the... 

    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... 

    Three dimensional pressure transient behavior study in stress sensitive reservoirs

    , Article Journal of Petroleum Science and Engineering ; Volume 152 , 2017 , Pages 204-211 ; 09204105 (ISSN) Moradi, M ; Shamloo, A ; Asadbegi, M ; Dezfuli, A. D ; Sharif University of Technology
    Elsevier B.V  2017
    Abstract
    Stress sensitivity is a phenomenon that affects reservoir rock properties, such as permeability and therefore changes the well pressure transient behavior. This paper aims to study these behaviors in stress sensitive reservoirs and evaluate the pressure loss in such reservoirs during the process of hydrocarbon production. A power model is used to correlate the changes in permeability with pore pressure. A novel semi-implicit three-dimensional finite element method has been employed to numerically solve the flow problem. The numerical results have been validated by analytical results obtained in a non-sensitive reservoir. Pressure drawdown test for different scenarios has been studied. The... 

    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... 

    Three-dimensional bioprinting of functional skeletal muscle tissue using gelatin methacryloyl-alginate bioinks

    , Article Micromachines ; Volume 10, Issue 10 , 2019 ; 2072666X (ISSN) Seyedmahmoud, R ; Çelebi Saltik, B ; Barros, N ; Nasiri, R ; Banton, E ; Shamloo, A ; Ashammakhi, N ; Dokmeci, M. R ; Ahadian, S ; Sharif University of Technology
    MDPI AG  2019
    Abstract
    Skeletal muscle tissue engineering aims to fabricate tissue constructs to replace or restore diseased or injured skeletal muscle tissues in the body. Several biomaterials and microscale technologies have been used in muscle tissue engineering. However, it is still challenging to mimic the function and structure of the native muscle tissues. Three-dimensional (3D) bioprinting is a powerful tool to mimic the hierarchical structure of native tissues. Here, 3D bioprinting was used to fabricate tissue constructs using gelatin methacryloyl (GelMA)-alginate bioinks. Mechanical and rheological properties of GelMA-alginate hydrogels were characterized. C2C12 myoblasts at the density 8 × 106 cells/mL... 

    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... 

    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... 

    The extended finite element method (X-FEM) for powder forming problems

    , Article Journal of Materials Processing Technology ; Volume 177, Issue 1-3 , 2006 , Pages 53-57 ; 09240136 (ISSN) Khoei, A. R ; Shamloo, A ; Anahid, M ; Shahim, K ; Sharif University of Technology
    2006
    Abstract
    In this paper, the eXtended Finite Element Method (X-FEM) is developed in pressure-sensitive plasticity of powder compaction process. In X-FEM, the need for mesh adaption to discontinuity interface is neglected and the process is accomplished by employing additional functions, which are added to approximate the displacement field of the elements located on the interface. The double-surface cap plasticity model is employed within the X-FEM framework in numerical simulation of powder material. The plasticity model includes a failure surface and an elliptical cap, which closes the open space between the failure surface and hydrostatic axis. The moving cap expands in the stress space according... 

    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... 

    Targeted pulmonary drug delivery in coronavirus disease (COVID-19) therapy: A patient-specific in silico study based on magnetic nanoparticles-coated microcarriers adhesion

    , Article International Journal of Pharmaceutics ; Volume 609 , 2021 ; 03785173 (ISSN) Ebrahimi, S ; Shamloo, A ; Alishiri, M ; Mozhdehbakhsh Mofrad, Y ; Akherati, F ; Sharif University of Technology
    Elsevier B.V  2021
    Abstract
    Since the beginning of the COVID-19 pandemic, nearly most confirmed cases develop respiratory syndromes. Using targeted drug delivery by microcarriers is one of the most important noteworthy methods for delivering drugs to the involved bronchi. This study aims to investigate the performance of a drug delivery that applies microcarriers to each branch of the lung under the influence of a magnetic field. The results show that by changing the inlet velocity from constant to pulsatile, the drug delivery performance to the lungs increases by ∼31%. For transferring the microcarriers to the right side branches (LUL and LLL), placing the magnet at zero height and ∼30° angle yields the best outcome.... 

    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... 

    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... 

    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... 

    Secondary flows, mixing, and chemical reaction analysis of droplet-based flow inside serpentine microchannels with different cross sections

    , Article Langmuir ; Volume 37, Issue 17 , 2021 , Pages 5118-5130 ; 07437463 (ISSN) Ghazimirsaeed, E ; Madadelahi, M ; Dizani, M ; Shamloo, A ; Sharif University of Technology
    American Chemical Society  2021
    Abstract
    Chemical bioreactions are an important aspect of many recent microfluidic devices, and their applications in biomedical science have been growing worldwide. Droplet-based microreactors are among the attractive types of unit operations, which utilize droplets for enhancement in both mixing and chemical reactions. In the present study, a finite-volume-method (FVM) numerical investigation is conducted based on the volume-of-fluid (VOF) applying for the droplet-based flows. This multiphase computational modeling is used for the study of the chemical reaction and mixing phenomenon inside a serpentine microchannel and explores the effects of the aspect ratio (i.e., AR = height/width) of... 

    Recent advances in the design and applications of amyloid-β peptide aggregation inhibitors for Alzheimer’s disease therapy

    , Article Biophysical Reviews ; Volume 11, Issue 6 , 2019 , Pages 901-925 ; 18672450 (ISSN) Jokar, S ; Khazaei, S ; Behnammanesh, H ; Shamloo, A ; Erfani, M ; Beiki, D ; Bavi, O ; Sharif University of Technology
    Springer  2019
    Abstract
    Alzheimer’s disease (AD) is an irreversible neurological disorder that progresses gradually and can cause severe cognitive and behavioral impairments. This disease is currently considered a social and economic incurable issue due to its complicated and multifactorial characteristics. Despite decades of extensive research, we still lack definitive AD diagnostic and effective therapeutic tools. Consequently, one of the most challenging subjects in modern medicine is the need for the development of new strategies for the treatment of AD. A large body of evidence indicates that amyloid-β (Aβ) peptide fibrillation plays a key role in the onset and progression of AD. Recent studies have reported... 

    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.... 

    Parametric study on mixing process in an in-plane spiral micromixer utilizing chaotic advection

    , Article Analytica Chimica Acta ; Volume 1022 , 2018 , Pages 96-105 ; 00032670 (ISSN) Vatankhah, P ; Shamloo, A ; Sharif University of Technology
    Abstract
    Recent advances in the field of microfabrication have made the application of high-throughput microfluidics feasible. Mixing which is an essential part of any miniaturized standalone system remains the key challenge. This paper proposes a geometrically simple micromixer for efficient mixing for high-throughput microfluidic devices. The proposed micromixer utilizes a curved microchannel (spiral microchannel) to induce chaotic advection and enhance the mixing process. It is shown that the spiral microchannel is more efficient in comparison to a straight microchannel, mixing wise. The pressure drop in the spiral microchannel is only slightly higher than that in the straight microchannel. It is... 

    Parametric study of droplet formation and characteristics within microfluidic devices - A case study

    , Article International Journal of Applied Mechanics ; Volume 12, Issue 7 , 2020 Salehi, S. S ; Shamloo, A ; Kazemzadeh Hannani, S ; Sharif University of Technology
    World Scientific  2020
    Abstract
    Droplet-based microfluidics technologies hold great attention in a wide range of applications, including chemical analysis, drug screening, and food industries. This work aimed to describe the effects of different physical properties of the two immiscible phases on droplet formation in a flow-focusing microfluidic device and determining proper flow rates to form a droplet within the desired size range. A numerical model was developed to solve the governing equations of two-phase flow and the results were validated with previous experimental results. The results demonstrate different types of droplet formation regimes from dripping to jetting and different production rates of droplets as a... 

    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...