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cytology
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Multi-objective dynamic cell formation problem: A stochastic programming approach
, Article Computers and Industrial Engineering ; Volume 98 , 2016 , Pages 323-332 ; 03608352 (ISSN) ; Rafiei, H ; Zohrevand, A. H ; Sharif University of Technology
Elsevier Ltd
Abstract
This paper addresses dynamic cell formation problem (DCFP) which has been explored vastly for several years. Although a considerable body of literature in this filed, two remarkable aspects have been significantly ignored so far, as uncertainty and human-related issues. In order to compensate such a shortage, this paper develops a bi-objective stochastic model. The first objective function of the developed model seeks to minimize total cost of machine procurement, machine relocation, inter-cell moves, overtime utilization, worker hiring/laying-off, and worker moves between cells; while the second objective function maximizes labor utilization of the cellular manufacturing system. In the...
Multifunctional conductive biomaterials as promising platforms for cardiac tissue engineering
, Article ACS Biomaterials Science and Engineering ; Volume 7, Issue 1 , 2021 , Pages 55-82 ; 23739878 (ISSN) ; Vahdat, S ; Baheiraei, N ; Razavi, M ; Norahan, M. H ; Baharvand, H ; Sharif University of Technology
American Chemical Society
2021
Abstract
Adult cardiomyocytes are terminally differentiated cells that result in minimal intrinsic potential for the heart to self-regenerate. The introduction of novel approaches in cardiac tissue engineering aims to repair damages from cardiovascular diseases. Recently, conductive biomaterials such as carbon- and gold-based nanomaterials, conductive polymers, and ceramics that have outstanding electrical conductivity, acceptable mechanical properties, and promoted cell-cell signaling transduction have attracted attention for use in cardiac tissue engineering. Nevertheless, comprehensive classification of conductive biomaterials from the perspective of cardiac cell function is a subject for...
Modification of rock/fluid and fluid/fluid interfaces during MEOR processes, using two biosurfactant producing strains of Bacillus stearothermophilus SUCPM#14 and Enterobacter cloacae: A mechanistic study
, Article Colloids and Surfaces B: Biointerfaces ; Vol. 117 , May , 2014 , pp. 457-465 ; ISSN: 09277765 ; Zeinolabedini Hezave, A ; Mohammadi, S ; Niazi, A ; Ayatollahi, S ; Sharif University of Technology
Abstract
During any microbial enhanced oil recovery process, both cells and the metabolic products of bacteria govern the tertiary oil recovery efficiency. However, very accurate examination is needed to find the functionality of these tiny creatures at different reservoir conditions. In this regard, the effect of cell structure on ultimate microbial recovery efficiency which is the most dominant mechanism based on the microorganism types (gram-negative or gram-positive) was systematically investigated. At the first stage, possible different active mechanisms using Bacillus stearothermophilus SUCPM#14 strain were tested using specially designed injection protocol, in situ and ex situ core flooding...
Modification of bacterial cellulose/keratin nanofibrous mats by a tragacanth gum-conjugated hydrogel for wound healing
, Article International Journal of Biological Macromolecules ; Volume 134 , 2019 , Pages 280-289 ; 01418130 (ISSN) ; Tamjid, E ; Eslahi, N ; Simchi, A ; Sharif University of Technology
Elsevier B.V
2019
Abstract
To enhance physicomechanical properties and bioactivity of fibrous membranes for wound dressing and tissue engineering applications, novel composite scaffolds consisting of fibrous mats and thermosensitive hydrogel particles were prepared by concurrent electrospinning and electrospraying technique. The composite scaffolds were composed of keratin/bacterial cellulose fibers (150 ± 43 nm) which are hybridized with hydrogel particles (500 nm to 2 μm) based on nonionic triblock copolymers conjugated with Tragacanth gum (TG). FTIR and H-NMR studies indicated ester reactions between carboxylated copolymers and TG through carbodiimide crosslinker chemistry. The hydrogel particles were uniformly...
Modeling self-assembly of the surfactants into biological bilayer membranes with special chemical structures using dissipative particle dynamics method
, Article Scientia Iranica ; Volume 23, Issue 3 , 2016 , Pages 942-950 ; 10263098 (ISSN) ; Pishevar, A. R ; Saidi, M. S ; Shirani, E ; Sharif University of Technology
Sharif University of Technology
2016
Abstract
The aim of this study is to simulate the self-assembly of the surfactant molecules with special chemical structure and bending stiffiness into bilayer membranes using a mesoscopic Dissipative Particle Dynamics (DPD) method. The surfactants are modeled with special chemical structure and bending stiffiness. To confirm that the novel model is physical, we determine the interaction parameters based on matching the compressibility and solubility of the DPD system with real physics of the uid. To match the mutual solubility for binary uids, we use the relation between DPD parameters and x-parameters in Flory-Huggins-type models. Unsaturated bonds can change the stiffiness of a lipid membrane,...
Modeling of cell deformation under external force using artificial neural network
, Article ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE), 12 November 2010 through 18 November 2010 ; Volume 2 , 2010 , Pages 659-665 ; 9780791844267 (ISBN) ; Vossoughi, G. R ; Abbasi, A. A ; Raeissi, P ; Sharif University of Technology
Abstract
Embryogenesis, regeneration and cell differentiation in microbiological entities are influenced by mechanical forces. Therefore, development of mechanical properties of these materials is important. Neural network technique is a useful method which can be used to obtain cell deformation by the means of force-geometric deformation data or vice versa. Prior to insertion in the needle injection process, deformation and geometry of cell under external point-load is a key element to understand the interaction between cell and needle. In this paper the goal is the prediction of cell membrane deformation under a certain force, and to visually estimate the force of indentation on the membrane from...
Modeling and optimization of gelatin-chitosan micro-carriers preparation for soft tissue engineering: using response surface methodology
, Article Materials Science and Engineering C ; Volume 75 , 2017 , Pages 545-553 ; 09284931 (ISSN) ; Mashayekhan, S ; Vakilian, S ; Sharif University of Technology
Abstract
Electrospray ionization is a wide spread technique for producing polymeric microcarriers (MCs) by applying electrostatic force and ionic cross-linker, simultaneously. In this study, fabrication process of gelatin-chitosan MCs and its optimization using the Response Surface Methodology (RSM) is reported. Gelatin/chitosan (G/C) blend ratio, applied voltage and feeding flow rate, their individual and interaction effects on the diameter and mechanical strength of the MCs were investigated. The obtained models for diameter and mechanical strength of MCs have a quadratic relationship with G/C blend ratio, applied voltage and feeding flow rate. Using the desirability curve, optimized G/C blend...
Milk cholesterol reduction using immobilized Lactobacillus acidophilus ATCC1643 in sodium-alginate
, Article International Journal of Food Engineering ; Volume 4, Issue 8 , 2008 ; 15563758 (ISSN) ; Alemzadeh, I ; Sharif University of Technology
Walter de Gruyter GmbH
2008
Abstract
Lactobacillus acidophilus is one of the major microorganisms which are famous for their effects on cholesterol. In this study, we have investigated the effect of L. acidophilus ATCC 1643 on removing the milk cholesterol and additionally, we have immobilized L. acidophilus ATCC1643 cells in sodium-alginate and observed its effect on milk cholesterol removing. Also, we have researched about the effect of some factors including: bacteria cells number (both free and immobilized cells) and immobilized cells bead size on cholesterol removing rate and ultimately the extracted results were compared together. The results indicated that free cells could reduce cholesterol to lower than 0.5mg/100ml...
Mid-defense: Mitigating protocol-level attacks in TOR using indistinguishability obfuscation
, Article 2014 11th International ISC Conference on Information Security and Cryptology, ISCISC 2014 ; 3- 4 September , 2014 , pp. 214-219 ; ISBN: 9781479953837 ; Najafi, S ; Jalili, R ; Sharif University of Technology
Abstract
TOR is one of the most famous anonymity networks. TOR works correctly when at least one honest relay exists along an established circuit. However, many attacks reveal anonymity of TOR communications by watermarking traffics, changing timings, counting cells per packets, and recently, introducing errors in cells. This paper focuses on protocol-level attacks which can de-anonymize users by changing a cell, and provides a solution for this attack by changing the way integrities of cells are checked. The proposed design allows all relays, not just the exit node, to check the integrity of cells, independently. In addition, this paper proposes a novel method, based on the concept of...
MicroRNA profiling reveals important functions of miR-125b and let-7a during human retinal pigment epithelial cell differentiation
, Article Experimental Eye Research ; Volume 190 , 2020 ; Satarian, L ; Moradi, S ; Sharifi Zarchi, A ; Günther, S ; Kamal, A ; Totonchi, M ; Mowla, S. J ; Braun, T ; Baharvand, H ; Sharif University of Technology
Academic Press
2020
Abstract
Retinal pigment epithelial (RPE) cells are indispensable for eye organogenesis and vision. To realize the therapeutic potential of in vitro-generated RPE cells for cell-replacement therapy of RPE-related retinopathies, molecular mechanisms of RPE specification and maturation need to be investigated. So far, many attempts have been made to decipher the regulatory networks involved in the differentiation of human pluripotent stem cells into RPE cells. Here, we exploited a highly-efficient RPE differentiation protocol to determine global expression patterns of microRNAs (miRNAs) during human embryonic stem cell (hESC) differentiation into RPE using small RNA sequencing. Our results revealed a...
Mathematical modeling and analytical solution of two-phase flow transport in an immobilized-cell photo bioreactor using the homotopy perturbation method (HPM)
, Article International Journal of Hydrogen Energy ; Volume 41, Issue 41 , 2016 , Pages 18405-18417 ; 03603199 (ISSN) ; Fattahi, M ; Sharif University of Technology
Elsevier Ltd
Abstract
In the present study, a theoretical model of a reaction–diffusion within an entrapped-cell photobioreactor packed with gel-granules containing immobilized photosynthetic bacterial cells is presented. The model is based on a system of two coupled nonlinear reaction–diffusion equations under steady-state condition for biochemical reactions occurring in the photobioreactor that describes the substrate and product concentration within the gel-granule. Simple analytical expressions for the concentration of substrate and product have been derived for all values of reaction–diffusion parameters, demonstrating competition between the diffusion and reaction in the gel-granule, using the homotopy...
Manipulating failure mechanism of rapid prototyped scaffolds by changing nodal connectivity and geometry of the pores
, Article Journal of Biomechanics ; Volume 45, Issue 16 , 2012 , Pages 2866-2875 ; 00219290 (ISSN) ; Bagheri, R ; Zehtab Yazdi, A ; Sharif University of Technology
2012
Abstract
The performance of cellular solids in biomedical applications relies strongly on a detailed understanding of the effects of pore topology on mechanical properties. This study aims at characterizing the failure mechanism of scaffolds based on nodal connectivity (number of struts that meet in joints) and geometry of the pores. Plastic models of scaffolds having the same relative density but different cubic and trigonal unit cells were designed and then fabricated via three dimensional (3-D) printing. Unit cells were repeated in different arrangements in 3-D space. An in-situ imaging technique was utilized to study the progressive deformation of the scaffold models. Different nodal...
Magnetic carbon nanotubes: preparation, physical properties, and applications in biomedicine
, Article Artificial Cells, Nanomedicine and Biotechnology ; Volume 46, Issue 7 , 2018 , Pages 1314-1330 ; 21691401 (ISSN) ; Farshbaf, M ; Annabi, N ; Kavetskyy, T ; Khalilov, R ; Saghfi, S ; Akbarzadeh, A ; Mousavi, S ; Sharif University of Technology
Abstract
Magnetic carbon nanotubes (MCNTs) have been widely studied for their potential applications in medicine, diagnosis, cell biology, analytical chemistry, and environmental technology. Introduction of MCNTs paved the way for the emergence of new approaches in nanobiotechnology and biomedicine as a result of their multifarious properties embedded within either the carbon nanotubes (CNTs) or magnetic parts. Numerous preparation techniques exists for functionalizing CNTs with magnetic nanoparticles, and these versatile strategies lay the ground for the generation of novel and versatile systems which are applicable to many industries and biological areas. Here, we review and discuss the recent...
Low-leakage soft error tolerant port-less configuration memory cells for FPGAs
, Article Integration, the VLSI Journal ; Volume 46, Issue 4 , September , 2013 , Pages 413-426 ; 01679260 (ISSN) ; Manzuri Shalmani, M. T ; Sharif University of Technology
2013
Abstract
As technology scales the area constraint is becoming less restrictive, but soft error rate and leakage current are drastically increased with technology down scaling. Therefore, in nano-scaled CMOS technology, the reduction of soft error rate and leakage current is the most important challenge in designing field programmable gate arrays (FPGA). To overcome these difficulties, based on the observations that most configuration bit-streams of FPGA are zeros across different designs and that configuration memory cells are not directly involved with signal propagation delays in FPGA, this paper presents a new family of configuration memory cells for FPGAs in nano-scaled CMOS technology. When...
Low-leakage soft error tolerant dual-port SRAM cells for cache memory applications
, Article Microelectronics Journal ; Volume 43, Issue 11 , November , 2012 , Pages 766-792 ; 00262692 (ISSN) ; Manzuri Shalmani, M. T ; Sharif University of Technology
2012
Abstract
As transistor dimensions are reduced due to technological advances, the area constraint is becoming less restrictive, but soft error rate, leakage current, and process variation are drastically increased. Therefore, in nano-scaled CMOS technology, soft error rate, leakage current and process variation are the most important issues in designing embedded cache memory. To overcome these challenges, and based on the observation that cache-resident memory values of ordinary programs exhibit a strong bias towards zero, this paper deals with new low leakage, hardened, and read-static-noise-margin-free SRAM memory cells for nano-scaled CMOS technology. These cells are completely hardened and cannot...
Liquid color recognition by using an optical reflection system
, Article Journal of Applied Sciences ; Volume 12, Issue 18 , 2012 , Pages 1917-1924 ; 18125654 (ISSN) ; Golnabi, H ; Sharif University of Technology
ANSInet
2012
Abstract
Operation of an optomechanical system for color reflection study is reported. The reported system consists of a double-fiber optical design and an electro-mechanical scanning system. In the double-fiber arrangement one fiber transmits the source light to the target surface and the second one sends the reflected light off the sample target to a photodetector. By scanning the double-fiber probe in one-direction reflection properties of different color liquid samples are investigated in this study. A cubic cell made of glass material is used as the liquid container and reflection signals are compared for different filled color liquids. The maximum reflection signals are: for the yellow color...
Leukocyte's nucleus segmentation using active contour in YCbCr colour space
, Article Proceedings of 2010 IEEE EMBS Conference on Biomedical Engineering and Sciences, IECBES 2010, 30 November 2010 through 2 December 2010, Kuala Lumpur ; 2010 , Pages 257-260 ; 9781424476008 (ISBN) ; Jahed, M ; Salehian, P ; Eslami, A ; Sharif University of Technology
2010
Abstract
Blood cell segmentation is a crucial part of many medical and laboratory procedures such as cell counting and blood cell disorder diagnosis. Among different types of blood cells, white blood cells are the most important clinically, as they suffer greatest from blood disorders. In this paper we propose a method for automatic segmentation of white blood cells nucleus. A distinctive function is used in YCbCr color space to segment the white blood cells nucleus. Next, the sub-images are extracted which contain the whole body of white blood cell nucleus. Then an active contour method is applied to the sub-images extracted from the previous step to accurately segment the cell nucleus boundary. Our...
Joint cell muting and user scheduling in multicell networks with temporal fairness
, Article Wireless Communications and Mobile Computing ; Volume 2018 , 2018 ; 15308669 (ISSN) ; Akar, N ; Khalaj, B. H ; Sharif University of Technology
Hindawi Limited
2018
Abstract
A semicentralized joint cell muting and user scheduling scheme for interference coordination in a multicell network is proposed under two different temporal fairness criteria. In the proposed scheme, at a decision instant, each base station (BS) in the multicell network employs a cell-level scheduler to nominate one user for each of its inner and outer sections and their available transmission rates to a network-level scheduler which then computes the potential overall transmission rate for each muting pattern. Subsequently, the network-level scheduler selects one pattern to unmute, out of all the available patterns. This decision is shared with all cell-level schedulers which then forward...
Ion Channel Based Bio-Synthetic Modulator for Diffusive Molecular Communication
, Article IEEE Transactions on Nanobioscience ; Volume 15, Issue 5 , 2016 , Pages 418-432 ; 15361241 (ISSN) ; Ahmadzadeh, A ; Schober, R ; Nasiri Kenari, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2016
Abstract
In diffusion-based molecular communication (DMC), a transmitter nanomachine is responsible for signal modulation. Thereby, the transmitter has to be able to control the release of the signaling molecules employed for representing the transmitted information. In nature, an important class of control mechanisms for releasing molecules from cells utilizes ion channels which are pore-forming proteins across the cell membrane. The opening and closing of the ion channels is controlled by a gating parameter. In this paper, an ion channel based modulator for DMC is proposed which controls the rate of molecule release from the transmitter by modulating a gating parameter signal. Exploiting the...
In vitro study: synthesis and evaluation of Fe3O4/CQD magnetic/fluorescent nanocomposites for targeted drug delivery, MRI, and cancer cell labeling applications
, Article Langmuir ; Volume 38, Issue 12 , 2022 , Pages 3804-3816 ; 07437463 (ISSN) ; Ahmadi, R ; Heydari, M ; Rahimipour, M. R ; Molaei, M. J ; Unsworth, L ; Sharif University of Technology
American Chemical Society
2022
Abstract
In the present study, first, Fe3O4nanoparticles were functionalized using glutaric acid and then composited with CQDs. Doxorubicin (DOX) drug was loaded to evaluate the performance of the nanocomposite for targeted drug delivery applications. The XRD pattern confirmed the presence of characteristic peaks of CQDs and Fe3O4. In the FTIR spectrum, the presence of carboxyl functional groups on Fe3O4/CQDs was observed; DOX (positive charge) is loaded onto Fe3O4/CQDs (negative charge) by electrostatic absorption. FESEM and AFM images showed that the particle sizes of Fe3O4and CQDs were 23-75 and 1-3 nm, respectively. The hysteresis curves showed superparamagnetic properties for Fe3O4and Fe3O4/CQDs...