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    ZnFe2O4 nanoparticles as radiosensitizers in radiotherapy of human prostate cancer cells

    , Article Materials Science and Engineering C ; Volume 46 , January , 2015 , Pages 394-399 ; 09284931 (ISSN) Meidanchi, A ; Akhavan, O ; Khoei, S ; Shokri, A. A ; Hajikarimi, Z ; Khansari, N ; Sharif University of Technology
    Elsevier Ltd  2015
    Nanoparticles of high-Z elements exhibit stronger photoelectric effects than soft tissues under gamma irradiation. Hence, they can be used as effective radiosensitizers for increasing the efficiency of current radiotherapy. In this work, superparamagnetic zinc ferrite spinel (ZnFe2O4) nanoparticles were synthesized by a hydrothermal reaction method and used as radiosensitizers in cancer therapy. The magnetic nanoparticles showed fast separation from solutions (e.g., ~ 1 min for 2 mg mL- 1 of the nanoparticles in ethanol) by applying an external magnetic field (~ 1 T). The ZnFe2O4 nanoparticles were applied in an in vitro radiotherapy of lymph node carcinoma of prostate cells (as high... 

    X-ray diffraction analysis and williamson-hall method in usdm model for estimating more accurate values of stress-strain of unit cell and super cells (2 × 2 × 2) of hydroxyapatite, confirmed by ultrasonic pulse-echo test

    , Article Materials ; Volume 14, Issue 11 , 2021 ; 19961944 (ISSN) Rabiei, M ; Palevicius, A ; Dashti, A ; Nasiri, S ; Monshi, A ; Doustmohammadi, A ; Vilkauskas, A ; Janusas, G ; Sharif University of Technology
    MDPI AG  2021
    Taking into account X-ray diffraction, one of the well-known methods for calculating the stress-strain of crystals is Williamson-Hall (W–H). The W-H method has three models, namely (1) Uniform deformation model (UDM); (2) Uniform stress deformation model (USDM); and (3) Uniform deformation energy density model (UDEDM). The USDM and UDEDM models are directly related to the modulus of elasticity (E). Young’s modulus is a key parameter in engineering design and materials development. Young’s modulus is considered in USDM and UDEDM models, but in all previous studies, researchers used the average values of Young’s modulus or they calculated Young’s modulus only for a sharp peak of an XRD pattern... 

    Whole cell mechanical property characterization based on mechanical properties of its cytoplasm and bio membrane

    , Article ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE), 9 November 2012 through 15 November 2012 ; Volume 2 , November , 2012 , Pages 545-551 ; 9780791845189 (ISBN) Abbasi, A. A ; Ahmadian, M. T ; Sharif University of Technology
    Analysis and investigation of the relation between different parts of biological cells such as biomembrane, cytoplasm and nucleus can help to better understand their behaviors and material properties. In this paper, first, the whole elastic properties of mouse oocyte and embryo cells have been computed by inverse finite element and Levenberg-Marquardt optimization algorithm and second, using the derived mechanical properties and the mechanical properties of its bio membrane from the literature, the mechanical properties of its cytoplasm has been characterized. It has been assumed that the cell behavior is as continues, isotropic, nonlinear and homogenous material for modeling. Matching the... 

    Viral infected cells reveal distinct polarization behavior; a polarimetric microscopy analysis on HSV infected Vero and HeLa cells

    , Article Journal of Quantitative Spectroscopy and Radiative Transfer ; Volume 262 , 2021 ; 00224073 (ISSN) Amiri, S ; Abedini, M ; Badieyan, S ; Vaezjalali, M ; Akhavan, O ; Sasanpour, P ; Sharif University of Technology
    Elsevier Ltd  2021
    The optical polarization properties of virus-infected cells have been measured, analyzed, and compared with the uninfected cells. In this regard, Vero and HeLa cells have been used as the host for Herpes simplex viruses (HSV). By using polarization microscopy imaging technique, the Mueller matrix images of infected and uninfected cells have been recorded. Through image processing and further analysis, the polarization properties of host cells are compared with their infected ones. For quantitative analysis, the multispectral Mueller matrix transformation (MMT) parameters (A and b) are calculated to identify the microstructural differentiations between uninfected and infected cells by HSV.... 

    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
    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... 

    Using intra-line level pairing for graceful degradation support in PCMs

    , Article Proceedings of IEEE Computer Society Annual Symposium on VLSI, ISVLSI, 8 July 2015 through 10 July 2015 ; Volume 07-10-July-2015 , 2015 , Pages 527-532 ; 21593469 (ISSN) ; 9781479987184 (ISBN) Asadinia, M ; Sarbazi Azad, H ; Sharif University of Technology
    IEEE Computer Society  2015
    In Phase-Change Memory (PCM), the number of writes a cell can take before wearing-out is limited and highly varied due to unbalanced write traffic and process variation. After the failure of weak cells and in presence of large number of failed lines, some techniques have been proposed to further prolong the lifetime of a PCM device by remapping failed lines to spares and salvage a PCM device with graceful degradation. Others rely on handling failures through inter-line pairing. Observations reveal that most of cells in a line are healthy when the line is marked as faulty by any of these proposals. To overcome this deficiency, we propose Intra-line Level Pairing(ILP), a technique that... 

    Unified model of brain tissue microstructure dynamically binds diffusion and osmosis with extracellular space geometry

    , Article Physical Review E - Statistical, Nonlinear, and Soft Matter Physics ; Volume 94, Issue 3 , 2016 ; 15393755 (ISSN) Yousefnezhad, M ; Fotouhi, M ; Vejdani, K ; Kamali Zare, P ; Sharif University of Technology
    American Physical Society  2016
    We present a universal model of brain tissue microstructure that dynamically links osmosis and diffusion with geometrical parameters of brain extracellular space (ECS). Our model robustly describes and predicts the nonlinear time dependency of tortuosity (λ=D/D∗) changes with very high precision in various media with uniform and nonuniform osmolarity distribution, as demonstrated by previously published experimental data (D = free diffusion coefficient, D∗ = effective diffusion coefficient). To construct this model, we first developed a multiscale technique for computationally effective modeling of osmolarity in the brain tissue. Osmolarity differences across cell membranes lead to changes... 

    Ultra-Dense 5G small cell deployment for fiber and wireless backhaul-aware infrastructures

    , Article IEEE Transactions on Vehicular Technology ; 2018 ; 00189545 (ISSN) Lotfi Rezaabad, A ; Beyranvand, H ; Salehi, J. A ; Maier, M ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2018
    In this paper, we study the cell planning problem for a two-tier cellular network containing two types of base stations (BSs)— i.e. with fiber backhaul, referred to as wired BSs (W-BSs), and BSs with wireless backhaul, referred to as unwired-BSs (U-BSs). In-band full-duplex wireless communications is used to connect U-BSs and W-BSs. We propose an algorithm to determine the minimum number of W-BSs and U-BSs to satisfy given cell and capacity coverage constraints. Furthermore, we apply our proposed non-dominated sorting genetic algorithm II (NSGA-II) to solve the joint cell and backhaul planning problem to minimize the cost of planning, while maximizing the coverage simultaneously.... 

    Two schemes for production of biosurfactant from Pseudomonas aeruginosa MR01: Applying residues from soybean oil industry and silica sol–gel immobilized cells

    , Article Colloids and Surfaces B: Biointerfaces ; Volume 152 , 2017 , Pages 159-168 ; 09277765 (ISSN) Bagheri Lotfabad, T ; Ebadipour, N ; Roostaazad, R ; Partovi, M ; Bahmaei, M ; Sharif University of Technology
    Elsevier B.V  2017
    Rhamnolipids are the most common biosurfactants and P. aeruginosa strains are the most frequently studied microorganisms for the production of rhamnolipids. Eco-friendly advantages and promising applications of rhamnolipids in various industries are the major reasons for pursuing the economic production of these biosurfactants. This study shows that cultivation of P. aeruginosa MR01 in medium contained inexpensive soybean oil refinery wastes which exhibited similar levels and homologues of rhamnolipids. Mass spectrometry indicated that the Rha-C10-C10 and Rha-Rha-C10-C10 constitute the main rhamnolipids in different cultures of MR01 including one of oil carbon source analogues. Moreover,... 

    Tunable Stopband HTS Josephson Junction Left-Handed Transmission Line with Independently Biasable Unit Cells

    , Article IEEE Transactions on Applied Superconductivity ; Volume 30, Issue 1 , 2020 Alizadeh, A ; Rejaei, B ; Fardmanesh, M ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2020
    A practical coplanar Josephson junction left-handed transmission line based on a step-edge junction technique is proposed in high-temperature superconductor technology and analyzed by electromagnetic simulations. The layout is designed for monolayer Yttrium Barium Copper Oxide thin film fabrication process. The propagation stopbands are tunable by controlling bias currents of Josephson junction arrays acting as parallel inductors for unit cells of the transmission line. Unlike the reported designs, each unit cell of our left-handed transmission line is independently biasable due to dc isolation of the unit cells along the transmission line. Being individually biasable is practically... 

    Toxicity of graphene and graphene oxide nanowalls against bacteria

    , Article ACS Nano ; Volume 4, Issue 10 , October , 2010 , Pages 5731-5736 ; 19360851 (ISSN) Akhavan, O ; Ghaderi, E ; Sharif University of Technology
    Bacterial toxicity of graphene nanosheets in the form of graphene nanowalls deposited on stainless steel substrates was investigated for both Gram-positive and Gram-negative models of bacteria. The graphene oxide nanowalls were obtained by electrophoretic deposition of Mg2+-graphene oxide nanosheets synthesized by a chemical exfoliation method. On the basis of measuring the efflux of cytoplasmic materials of the bacteria, it was found that the cell membrane damage of the bacteria caused by direct contact of the bacteria with the extremely sharp edges of the nanowalls was the effective mechanism in the bacterial inactivation. In this regard, the Gram-negative Escherichia coli bacteria with an... 

    Tissue growth into three-dimensional composite scaffolds with controlled micro-features and nanotopographical surfaces

    , Article Journal of Biomedical Materials Research - Part A ; Volume 101, Issue 10 , 2013 , Pages 2796-2807 ; 15493296 (ISSN) Tamjid, E ; Simchi, A ; Dunlop, J. W. C ; Fratzl, P ; Bagheri, R ; Vossoughi, M ; Sharif University of Technology
    Controlling topographic features at all length scales is of great importance for the interaction of cells with tissue regenerative materials. We utilized an indirect three-dimensional printing method to fabricate polymeric scaffolds with pre-defined and controlled external and internal architecture that had an interconnected structure with macro- (400-500 μm) and micro- (∼25 μm) porosity. Polycaprolactone (PCL) was used as model system to study the kinetics of tissue growth within porous scaffolds. The surface of the scaffolds was decorated with TiO2 and bioactive glass (BG) nanoparticles to the better match to nanoarchitecture of extracellular matrix (ECM). Micrometric BG particles were... 

    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
    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... 

    The synergistic effect of surface topography and sustained release of TGF-β1 on myogenic differentiation of human mesenchymal stem cells

    , Article Journal of Biomedical Materials Research - Part A ; Volume 104, Issue 7 , 2016 , Pages 1610-1621 ; 15493296 (ISSN) Moghadasi Boroujeni, S ; Mashayekhan, S ; Vakilian, S ; Ardeshirylajimi, A ; Soleimani, M ; Sharif University of Technology
    John Wiley and Sons Inc 
    A combination of topographical cues and controlled release of biochemical factors is a potential platform in controlling stem cells differentiation. In this study the synergistic effect of nanotopography and sustained release of biofunctional transforming growth factor beta 1 (TGF-β1) on differentiation of human Wharton's Jelly-derived mesenchymal stem cell (hWJ-derived UC-MSCs) toward myogenic lineage was investigated. In order to achieve a sustained release of TGF-β1, this factor was encapsulated within chitosan nanoparticles. Afterwards the aligned composite mats were fabricated using poly-E-caprolacton (PCL) containing TGF-β1-loaded chitosan nanoparticles and poly-L-lactic acid (PLLA).... 

    Thermal conductivity of the cell membrane in the presence of cholesterol and amyloid precursor protein

    , Article Physical Review E ; Volume 102, Issue 4 , 2020 Rafieiolhosseini, N ; Ejtehadi, M. R ; Sharif University of Technology
    American Physical Society  2020
    The cell membrane is responsible for the transportation of heat between inside and outside the cell. Whether the thermal properties of the cell membrane are affected by the cholesterol concentration or the membrane proteins has not been investigated so far. Although the experimental measurement of the membrane thermal conductivity was not available until very recently, computational methods have been widely used for this purpose. In this study, we carry out molecular dynamics simulations to investigate the relation between the concentration of cholesterol and the thermal conductivity of a model membrane. Our results suggest an increase in the membrane thermal conductivity upon increasing the... 

    Theoretical modeling of actin-retrograde-flow passing clusters of confined T cell receptors

    , Article Mathematical Biosciences ; Volume 283 , 2017 , Pages 1-6 ; 00255564 (ISSN) Ghasemi V., A ; Firoozabadi, B ; Saidi, M. S ; Sharif University of Technology
    Elsevier Inc  2017
    Through the activation process of T cells, actin filaments move from the cell periphery toward the cell center. The moving filaments engage with T cell receptors and thus contribute to transportation of the signaling molecules. To study the connection between the moving actin filaments and T cell receptors, an experiment available in the literature has measured filaments flow velocity passing over a region of confined clusters of receptors. It shows that flow velocity decreases in the proximity of the receptors, and then regains its normal value after traversing the region, suggesting a dissipative friction-like connection. In this work, we develop a minimal theoretical model to re-examine... 

    The nanofibrous PAN-PANi scaffold as an efficient substrate for skeletal muscle differentiation using satellite cells

    , Article Bioprocess and Biosystems Engineering ; Volume 39, Issue 7 , 2016 , Pages 1163-1172 ; 16157591 (ISSN) Hosseinzadeh, S ; Mahmoudifard, M ; Mohamadyar Toupkanlou, F ; Dodel, M ; Hajarizadeh, A ; Adabi, M ; Soleimani, M ; Sharif University of Technology
    Springer Verlag 
    Among polymers, polyaniline (PANi) has been introduced as a good candidate for muscle regeneration due to high conductivity and also biocompatibility. Herein, for the first time, we report the use of electrospun nanofibrous membrane of PAN-PANi as efficient scaffold for muscle regeneration. The prepared PAN-PANi electrospun nanofibrous membrane was characterized by scanning electron microscopy (SEM), Attenuated total reflectance fourier transform infrared spectroscopy (ATR-FTIR) and tensile examination. The softer scaffolds of non-composite electrospun nanofibrous PAN govern a higher rate of cell growth in spite of lower differentiation value. On the other hand, PAN-PANi electrospun... 

    The importance of fluid-structure interaction simulation for determining the mechanical stimuli of endothelial cells and atheroprone regions in a coronary bifurcation

    , Article Scientia Iranica ; Volume 23, Issue 1 , 2016 , Pages 228-237 ; 10263098 (ISSN) Pakravan, H. A ; Saidi, M. S ; Firoozabadi, B ; Sharif University of Technology
    Sharif University of Technology  2016
    The function and morphology of Endothelial Cells (ECs) play a key role in atherosclerosis. The mechanical stimuli of ECs, such as Wall Shear Stress (WSS) and arterial wall strain, greatly inuence the function and morphology of these cells. The present article deals with computations of these stimuli for a 3D model of a healthy coronary artery bifurcation. The focus of the study is to propose an accurate method for computations of WSS and strains. Two approaches are considered: Coupled simultaneous simulation of arterial wall and blood flow, called fluid-Structure Interaction (FSI) simulation, and decoupled, which simulates each domain (fluid and solid domain) separately. The study... 

    The impact of zirconium oxide nanoparticles content on alginate dialdehyde-gelatin scaffolds in cartilage tissue engineering

    , Article Journal of Molecular Liquids ; Volume 335 , 2021 ; 01677322 (ISSN) Ghanbari, M ; Salavati Niasari, M ; Mohandes, F ; Firouzi, Z ; Mousavi, S.-D ; Sharif University of Technology
    Elsevier B.V  2021
    The desire to regenerate and repair native tissues can be immediately performed by multiple tissue engineering procedures. Gelatin and alginate are biocompatible and biodegradable polymers. The addition of ZrO2 nanoparticles (NPs) into the alginate-gelatin hydrogel is considered to improve mechanical and chemical properties. Therefore, nanocomposite hydrogels have been manufactured by the freeze-drying procedure utilizing oxidized alginate-gelatin with ZrO2 NPs as a reinforcement. The fabricated nanocomposite hydrogels were character-ized by FTIR, FESEM, and rheometer. The hydrogels containing a higher ZrO2 NPs content (1.5%) have better mechanical properties than the hydrogels without NPs.... 

    The effect of the physical properties of the substrate on the kinetics of cell adhesion and crawling studied by an axisymmetric diffusion-energy balance coupled model

    , Article Soft Matter ; Volume 11, Issue 18 , Mar , 2015 , Pages 3693-3705 ; 1744683X (ISSN) Samadi Dooki, A ; Shodja, H. M ; Malekmotiei, L ; Sharif University of Technology
    Royal Society of Chemistry  2015
    In this paper an analytical approach to study the effect of the substrate physical properties on the kinetics of adhesion and motility behavior of cells is presented. Cell adhesion is mediated by the binding of cell wall receptors and substrate's complementary ligands, and tight adhesion is accomplished by the recruitment of the cell wall binders to the adhesion zone. The binders' movement is modeled as their axisymmetric diffusion in the fluid-like cell membrane. In order to preserve the thermodynamic consistency, the energy balance for the cell-substrate interaction is imposed on the diffusion equation. Solving the axisymmetric diffusion-energy balance coupled equations, it turns out that...