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    Fluids Flow Simulation in the Cell Influenced the Focal Adhesions

    , Ph.D. Dissertation Sharif University of Technology Nikmaneshi, Mohammad Reza (Author) ; Firoozabadi, Bahar (Supervisor) ; saidi, Mohammad said (Co-Advisor)
    Abstract
    In the present thesis, intracellular fluid flows have investigated for study cell motions. It is due to firmly relation between the cell motion and these flows. Generally, the cell firstly adheres to a surface, then, moves forward with the effects of the internal fluid flows. In this study, the cell structure is invided to two general parts; the front part of the cell and the cell body. The front part of the cell plays a essential roles in the cell motion, however, the cell body is considered as a extra cargo that is carried by the front of the cell. Therefor, in the present modellings, the front part is only considered. Here, using four different models for the front part of the cell, many... 

    Studies of the Interaction between Actins Flow and Cell Adhesion Nucleation in Macro-and Micro-scale

    , Ph.D. Dissertation Sharif University of Technology Ghasemi Varnamkhasti, Amir (Author) ; Firouzabadi, Bahar (Supervisor) ; Saeedi, Mohammad Saeed (Supervisor)
    Abstract
    The network of actin filaments is one of the three elements of the Cytoskeleton and plays a role in cell shape and migration. The actin network is dynamic; it (de)polymerizes, and in migrating and spreading cells, it is in a retrograde motion from the cell periphery toward cell nucleus. Adhesion points, which link the cytoskeleton to the extracellular matrix, interact with the actin retrograde flow. Actin filaments can be identified in two distinct regions in which their structure, flow velocity, driving force and size of the adhesions are different; the outer region is called Lamellipodium and the inner one Lamellum. In macro scale and regarding spreading cells, considering adhesions... 

    Analytical Solutions of Actin-Retrograde-Flow in a Circular Stationary Cell: A Mechanical Point of View

    , Article Bulletin of Mathematical Biology ; Vol. 76, issue. 3 , March , 2014 , p. 744-760 ; 00928240 Ghasemi, V., A ; Firoozabadi, B ; Saidi, M. S ; Sharif University of Technology
    Abstract
    The network of actin filaments in the lamellipodium (LP) of stationary and migrating cells flows in a retrograde direction, from the membrane periphery toward the cell nucleus. We have theoretically studied this phenomenon in the circular stationary (fully spread) cells. Adopting a continuum view on the LP actin network, new closed-form solutions are provided for the actin-retrograde-flow (ARF) in a polar coordinate system. Due to discrepancy in the mechanical models of the actin network in the ARF regime, solutions are provided for both assumptions of solid and fluid behavior. Other involved phenomena, including polymerizing machine at the membrane periphery, cytosol drag, adhesion... 

    Continuum model of actin-myosin flow

    , Article 2013 20th Iranian Conference on Biomedical Engineering, ICBME 2013 ; December , 2013 , Pages 98-102 Nikmaneshi, M. R ; Firoozabadi, B ; Saidi, M. S ; Sharif University of Technology
    IEEE Computer Society  2013
    Abstract
    The front part of a cell is divided to two regions called lamellum and lamellipodium (lamellipodial). This part plays an essential role for cell migration. Indeed, there are many protein filaments called actin in lamellum and lamellipodium, which induce the cell motion with polymerization in the leading edge of the cell. The actin filaments adhere to the extracellular matrix (ECM) by means of focal adhesions and they have contact by myosin motor proteins. The myosin motor proteins cause actin retrograde and anterograde flow exerted contractile stress on them. The focal adhesions exert frictional stress on the actin filaments. In this work, we developed a two-dimensional continuum model of...