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    Inertial particle focusing in serpentine channels on a centrifugal platform

    , Article Physics of Fluids ; Volume 30, Issue 1 , 2018 ; 10706631 (ISSN) Shamloo, A ; Mashhadian, A ; Sharif University of Technology
    American Institute of Physics Inc  2018
    Abstract
    Inertial particle focusing as a powerful passive method is widely used in diagnostic test devices. It is common to use a curved channel in this approach to achieve particle focusing through balancing of the secondary flow drag force and the inertial lift force. Here, we present a focusing device on a disk based on the interaction of secondary flow drag force, inertial lift force, and centrifugal forces to focus particles. By choosing a channel whose cross section has a low aspect ratio, the mixing effect of the secondary flow becomes negligible. To calculate inertial lift force, which is exerted on the particle from the fluid, the interaction between the fluid and particle is investigated... 

    Numerical analysis of a dielectrophoresis field-flow fractionation device for the separation of multiple cell types

    , Article Journal of Separation Science ; Volume 40, Issue 20 , 2017 , Pages 4067-4075 ; 16159306 (ISSN) Shamloo, A ; Kamali, A ; Sharif University of Technology
    2017
    Abstract
    In this study, a dielectrophoresis field-flow fractionation device was analyzed using a numerical simulation method and the behaviors of a set of different cells were investigated. By reducing the alternating current frequency of the electrodes from the value used in the original setup configuration and increasing the number of exit channels, total discrimination in cell trajectories and subsequent separation of four cell types were achieved. Cells were differentiated based on their size and dielectric response that are represented in their real part of Clausius–Mossotti factor at different frequencies. A number of novel designs were also proposed based on the original setup configuration.... 

    Local impact of Stone–Wales defect on a single layer GNRFET

    , Article Physics Letters, Section A: General, Atomic and Solid State Physics ; Volume 384, Issue 7 , 2020 Shamloo, H ; Nazari, A ; Faez, R ; Shahhoseini, A ; Sharif University of Technology
    Elsevier B.V  2020
    Abstract
    In this work, a new structure of single layer armchair graphene nanoribbon field effect transistor with the Stone–Wales (SW) defect (SWGNRFET) is studied. The simulations are solved with Poisson–Schrödinger equation self-consistently by using Non-Equilibrium Green Function (NEGF) and in the real space approach. The energy band structure is obtained by approximation tight-binding method. The results show that displacement of a defect in the width of the channel of the new structure is led to 50% increase in ION/IOFF ratio only by rotating of a C–C (Carbon–Carbon) bond with similar behavior. But, a remarkable increase of 300% in ION/IOFF ratio is obtained by a “dual center” defect. The results... 

    Drug delivery performance of nanocarriers based on adhesion and interaction for abdominal aortic aneurysm treatment

    , Article International Journal of Pharmaceutics ; Volume 594 , 2021 ; 03785173 (ISSN) Ebrahimi, S ; Vatani, P ; Amani, A ; Shamloo, A ; Sharif University of Technology
    Elsevier B.V  2021
    Abstract
    Targeted drug delivery using nanocarriers (NCs) is one of the novel techniques that has recently been used to improve drug delivery to the Abdominal aortic aneurysm (AAA) disease. The purpose of this study is to evaluate the surface density of NCs (SDNC) adhered via ligand-receptor binding to the inner wall of AAA. For this purpose, fluid–structure interaction (FSI) analysis was first performed for the patient-specific and ideal AAA models. Then, by injecting NCs into the aortic artery, the values of SDNC adhered to and interacted with AAA wall were obtained. Two types of NCs, liposomes, and solid particles in four different diameters, were used to investigate the effect of the diameter and... 

    Integrating hydrodynamic and acoustic cell separation in a hybrid microfluidic device: a numerical analysis

    , Article Acta Mechanica ; Volume 233, Issue 5 , 2022 , Pages 1881-1894 ; 00015970 (ISSN) Ashkezari, A. H. K ; Dizani, M ; Shamloo, A ; Sharif University of Technology
    Springer  2022
    Abstract
    Cell separation microfluidic devices have evolved into a multitude of biomedical and clinical research. Nonetheless, many critical issues remain in the way of achieving an excellent separation of target cells from a heterogeneous sample. Parallel to the abundant experimental studies related to the hybrid microfluidic methods, it is easy to perceive the lack of numerical investigations in order to optimize the separation process and its accuracy. In this study, for the first time to the best of our knowledge, a hybrid system by integrating acoustophoresis and pinched-flow fractionation (PFF) is proposed to achieve a viable system for a wide-range, precise separation. Employing the ultrasound... 

    Analyzing mixing quality in a curved centrifugal micromixer through numerical simulation

    , Article Chemical Engineering and Processing: Process Intensification ; 2017 ; 02552701 (ISSN) Shamloo, A ; Vatankhah, P ; Akbari, A ; Sharif University of Technology
    Elsevier B.V  2017
    Abstract
    The Lab On a CD (LOCD), also known as Centrifugal Microfluidics, has evolved into a sophisticated platform for performing biomedical assays due to its marvelous miniaturization and accurate simulation of biological reactions. Among the numerous applications of the LOCD is fluid mixing. In this paper a centrifugal, serpentine micromixer is simulated and reformed toward better mixing performance. The micromixer was chosen to be curved as a curved design was found to be thrice as functional and compact as a rectilinear design, mixing-wise. The two angular velocity and opening radius parameters were originally hypothesized to affect mixing performance. Effect of angular velocity was studied over... 

    Numerical simulation of heat transfer in mixed electroosmotic pressure-driven flow in straight microchannels

    , Article Journal of Thermal Science and Engineering Applications ; Volume 8, Issue 2 , 2016 ; 19485085 (ISSN) Shamloo, A ; Merdasi, A ; Vatankhah, P ; Sharif University of Technology
    American Society of Mechanical Engineers (ASME)  2016
    Abstract
    This paper investigates two-dimensional, time-independent elecroosmotic pressuredriven flow generated by a direct current electric potential with asymmetrical and symmetrical zeta potential distributions along the microchannel walls. Fluid flow through the horizontal microchannel is simulated using a numerical method. Two different cases are proposed to study the effect of electric potential on the flow field. First, negative electric potential is applied on the microchannel walls. In this case, large segments with negative electric potential are initially placed on the first half of the microchannel walls with two different arrangements. Afterward, smaller segments with negative electric... 

    Numerical simulation of centrifugal serpentine micromixers and analyzing mixing quality parameters

    , Article Chemical Engineering and Processing: Process Intensification ; Volume 104 , 2016 , Pages 243-252 ; 02552701 (ISSN) Shamloo, A ; Madadelahi, M ; Akbari, A ; Sharif University of Technology
    Elsevier, B.V  2016
    Abstract
    Centrifugal microfluidics or the Lab on a CD (LOCD) has developed vast applications in biomedical researches and analyses. Fluid mixing is an application of the LOCD. In this paper, multiple centrifugal micromixers were simulated. Various parameters were originally presumed to have an effect on mixing performance. These parameters include inlet angle, angular velocity, cross-sectional profile, perpendicular length ratio and the number of channels in series. They were each analyzed through simulations. It was gathered that the inlet angle does not significantly affect the mixing quality. Increasing angular velocity steadily increases mixing quality for all geometries. The vertical triangular... 

    Designing a polymerase chain reaction device working with radiation and convection heat transfer

    , Article 2017 International Conference on Nanomaterials and Biomaterials, ICNB 2017, 11 December 2017 through 13 December 2017 ; Volume 350, Issue 1 , 2018 ; 17578981 (ISSN) Madadelahi, M ; Kalan, K ; Shamloo, A ; Sharif University of Technology
    Institute of Physics Publishing  2018
    Abstract
    Gene proliferation is vital for infectious and genetic diseases diagnosis from a blood sample, even before birth. In addition, DNA sequencing, genetic finger-print analyzing, and genetic mutation detecting can be mentioned as other procedures requiring gene reproduction. Polymerase chain reaction, briefly known as PCR, is a convenient and effective way to accomplish this task; where the DNA containing sample faces three temperature phases alternatively. These phases are known as denaturation, annealing, and elongation/extension which in this study -regarding the type of the primers and the target DNA sequence- are set to occur at 95, 58, and 72 degrees of Celsius. In this study, a PCR device... 

    Analyzing mixing quality in a curved centrifugal micromixer through numerical simulation

    , Article Chemical Engineering and Processing: Process Intensification ; Volume 116 , 2017 , Pages 9-16 ; 02552701 (ISSN) Shamloo, A ; Vatankhah, P ; Akbari, A ; Sharif University of Technology
    Elsevier B.V  2017
    Abstract
    The Lab On a CD (LOCD), also known as Centrifugal Microfluidics, has evolved into a sophisticated platform for performing biomedical assays due to its marvelous miniaturization and accurate simulation of biological reactions. Among the numerous applications of the LOCD is fluid mixing. In this paper a centrifugal, serpentine micromixer is simulated and reformed toward better mixing performance. The micromixer was chosen to be curved as a curved design was found to be thrice as functional and compact as a rectilinear design, mixing-wise. The two angular velocity and opening radius parameters were originally hypothesized to affect mixing performance. Effect of angular velocity was studied over... 

    Design and fabrication of a two-phase diamond nanoparticle aided fast PCR device

    , Article Analytica Chimica Acta ; Volume 1068 , 2019 , Pages 28-40 ; 00032670 (ISSN) Madadelahi, M ; Ghazimirsaeed, E ; Shamloo, A ; Sharif University of Technology
    Elsevier B.V  2019
    Abstract
    Polymerase Chain Reaction (PCR) is an important and prevalent technique in biotechnology because of its crucial role in cloning DNA fragments and diagnostic applications. In the present study, a high-throughput two-phase PCR device is designed and fabricated which utilizes a serpentine microchannel together with a spiral structure. The former is for the droplet-generation and mixing and the latter is for the thermal cycling process. Moreover, the effect of diamond nanoparticles (diamondNP) on the performance of PCR is also investigated while using commercial PCR devices and the fabricated PCR device designed in this study. Using numerical simulation, it is shown that within the simple and... 

    Numerical simulation of mixing and heat transfer in an integrated centrifugal microfluidic system for nested-PCR amplification and gene detection

    , Article Sensors and Actuators, B: Chemical ; Volume 283 , 2019 , Pages 831-841 ; 09254005 (ISSN) Naghdloo, A ; Ghazimirsaeed, E ; Shamloo, A ; Sharif University of Technology
    Elsevier B.V  2019
    Abstract
    Nucleic acid amplification via polymerase chain reaction (PCR) is one of the essential and powerful methods used in a myriad of bio-assays in clinical laboratories. Application of microfluidic devices in biologically-related processes like PCR can result in the usage of less volume of reactant samples and reduce the processing time. By implementing PCR systems on centrifugal microfluidic platforms, automation and portability can be easily achieved. Although several methods have been developed, most of them are still dealing with challenges of the required high processing time. This study presents the numerical simulation of a fully automated PCR system with the goal of enhancing the mixing... 

    PASylation enhances the stability, potency, and plasma half-life of interferon α-2a: A molecular dynamics simulation

    , Article Biotechnology Journal ; Volume 15, Issue 8 , 2020 Shamloo, A ; Rostami, P ; Mahmoudi, A ; Sharif University of Technology
    Wiley-VCH Verlag  2020
    Abstract
    In this study, the effectiveness of PASylation in enhancing the potency and plasma half-life of pharmaceutical proteins has been accredited as an alternative technique to the conventional methods such as PEGylation. Proline, alanine, and serine (PAS) chain has shown some advantages including biodegradability improvement and plasma half-life enhancement while lacking immunogenicity or toxicity. Although some experimental studies have been performed to find the mechanism behind PASylation, the detailed mechanism of PAS effects on the pharmaceutical proteins has remained obscure, especially at the molecular level. In this study, the interaction of interferon α-2a (IFN) and PAS chain is... 

    Investigation of a two-step device implementing magnetophoresis and dielectrophoresis for separation of circulating tumor cells from blood cells

    , Article Engineering in Life Sciences ; Volume 20, Issue 7 , 2020 , Pages 296-304 Shamloo, A ; Yazdani, A ; Saghafifar, F ; Sharif University of Technology
    Wiley-VCH Verlag  2020
    Abstract
    Identifying tumor cells from a pool of other cells has always been an appealing topic for different purposes. The objective of this study is to discriminate circulating tumor cells (CTCs) from blood cells for diagnostic purposes in a novel microfluidic device using two active methods: magnetophoresis and dielectrophoresis. The most specific feature of this device is the differentiation of CTCs without labeling them in order to achieve a more reliable and less complicated method. This device was analyzed and evaluated using finite element method. Four cell lines are separated in this device containing red blood cells, platelets, white blood cells, and CTCs. Primarily, red blood cells and... 

    Cancer cell enrichment on a centrifugal microfluidic platform using hydrodynamic and magnetophoretic techniques

    , Article Scientific Reports ; Volume 11, Issue 1 , 2021 ; 20452322 (ISSN) Shamloo, A ; Naghdloo, A ; Besanjideh, M ; Sharif University of Technology
    Nature Research  2021
    Abstract
    Isolation of rare cancer cells is one of the important and valuable stages of cancer research. Regarding the rarity of cancer cells in blood samples, it is important to invent an efficient separation device for cell enrichment. In this study, two centrifugal microfluidic devices were designed and fabricated for the isolation of rare cancer cells. The first design (passive plan) employs a contraction–expansion array (CEA) microchannel which is connected to a bifurcation region. This device is able to isolate the target cells through inertial effects and bifurcation law. The second design (hybrid plan) also utilizes a CEA microchannel, but instead of using the bifurcation region, it is... 

    An integrative method to increase the reliability of conventional double emulsion method

    , Article Analytica Chimica Acta ; Volume 1197 , 2022 ; 00032670 (ISSN) Mashhadian, A ; Afjoul, H ; Shamloo, A ; Sharif University of Technology
    Elsevier B.V  2022
    Abstract
    Polymeric microspheres which can load biomolecules, cells and active agents play an important role in tissue engineering and drug delivery systems. The conventional double emulsion method has been frequently used to fabricate polymeric microspheres. However, this method has two major shortcomings: the complicated fabrication process which makes it difficult to predict the characteristics of the final microspheres while the size distribution of the microspheres has a wide range. In this study, we eliminate the shortcomings of the conventional double emulsion method and increase its performance without decreasing its high production rate. This can make the proposed modified method a promising... 

    Numerical optimization and inverse study of a microfluidic device for blood plasma separation

    , Article European Journal of Mechanics, B/Fluids ; Volume 57 , 2016 , Pages 31-39 ; 09977546 (ISSN) Shamloo, A ; Vatankhah, P ; Bijarchi, M. A ; Sharif University of Technology
    Elsevier Ltd  2016
    Abstract
    In this paper, a passive microfluidic device for continuous real time blood plasma separation has been studied and optimized. A numerical model is used to solve both the fluid flow and the particles confined within it. Red blood cells are considered as particles with diameter of 7μm. A parametric study is performed in order to characterize the effect of different parameters on separation and purity efficiency. In this study, four different variables were introduced to design the microfluidic device for blood plasma separation including: the angle between the daughter channels and the main channel, the widths, the diffuse angle and the number of daughter channels. Results show that the... 

    Fluid–structure interaction simulation of a cerebral aneurysm: effects of endovascular coiling treatment and aneurysm wall thickening

    , Article Journal of the Mechanical Behavior of Biomedical Materials ; Volume 74 , 2017 , Pages 72-83 ; 17516161 (ISSN) Shamloo, A ; Nejad, M. A ; Saeedi, M ; Sharif University of Technology
    2017
    Abstract
    In the present study, we investigate the effect of the hemodynamic factors of the blood flow on the cerebral aneurysms. To this end, a hypothetical geometry of the aneurysm in the circle of Willis, located in the bifurcation point of the anterior cerebral artery (ACA) and anterior communicating artery (ACoA) is modeled in a three-dimensional manner. Three cases are chosen in the current study: an untreated thin wall (first case), untreated thick wall (second case), and a treated aneurysm (third case). The effect of increasing the aneurysm wall thickness on the deformation and stress distribution of the walls are studied. The obtained results showed that in the second case, a reduction in the... 

    A three-dimensional micromechanical model of brain white matter with histology-informed probabilistic distribution of axonal fibers

    , Article Journal of the Mechanical Behavior of Biomedical Materials ; Volume 88 , 2018 , Pages 288-295 ; 17516161 (ISSN) Yousefsani, S. A ; Farahmand, F ; Shamloo, A ; Sharif University of Technology
    Elsevier Ltd  2018
    Abstract
    This paper presents a three-dimensional micromechanical model of brain white matter tissue as a transversely isotropic soft composite described by the generalized Ogden hyperelastic model. The embedded element technique, with corrected stiffness redundancy in large deformations, was used for the embedment of a histology-informed probabilistic distribution of the axonal fibers in the extracellular matrix. The model was linked to a multi-objective, multi-parametric optimization algorithm, using the response surface methodology, for characterization of material properties of the axonal fibers and extracellular matrix in an inverse finite element analysis. The optimum hyperelastic... 

    A plasmonic gold nanofilm-based microfluidic chip for rapid and inexpensive droplet-based photonic PCR

    , Article Scientific Reports ; Volume 11, Issue 1 , December , 2021 ; 20452322 (ISSN) Jalili, A ; Bagheri, M ; Shamloo, A ; Kazemipour Ashkezari, A. H ; Sharif University of Technology
    Nature Research  2021
    Abstract
    Polymerase chain reaction (PCR) is a powerful tool for nucleic acid amplification and quantification. However, long thermocycling time is a major limitation of the commercial PCR devices in the point-of-care (POC). Herein, we have developed a rapid droplet-based photonic PCR (dpPCR) system, including a gold (Au) nanofilm-based microfluidic chip and a plasmonic photothermal cycler. The chip is fabricated by adding mineral oil to uncured polydimethylsiloxane (PDMS) to suppress droplet evaporation in PDMS microfluidic chips during PCR thermocycling. A PDMS to gold bonding technique using a double-sided adhesive tape is applied to enhance the bonding strength between the oil-added PDMS and the...