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Polyethylene glycol-coated porous magnetic nanoparticles for targeted delivery of chemotherapeutics under magnetic hyperthermia condition
, Article International Journal of Hyperthermia ; 2018 ; 02656736 (ISSN) ; Hedayatnasab, Z ; Karimian, H ; Sarraf, M ; Yeong, C. H ; Madaah Hosseini, H. R ; Abu Kasim, N. H ; Wong, T. W ; Rahman, N. A ; Sharif University of Technology
Taylor and Francis Ltd
2018
Abstract
Purpose: Although magnetite nanoparticles (MNPs) are promising agents for hyperthermia therapy, insufficient drug encapsulation efficacies inhibit their application as nanocarriers in the targeted drug delivery systems. In this study, porous magnetite nanoparticles (PMNPs) were synthesized and coated with a thermosensitive polymeric shell to obtain a synergistic effect of hyperthermia and chemotherapy. Materials and methods: PMNPs were produced using cetyltrimethyl ammonium bromide template and then coated by a polyethylene glycol layer with molecular weight of 1500 Da (PEG1500) and phase transition temperature of 48 ± 2 °C to endow a thermosensitive behavior. The profile of drug release...
Study and Preparation of Coated Drug by PEG Biopolymer (PEGylation) for Release Controlling
, M.Sc. Thesis Sharif University of Technology ; Vossoughi, Manoochehr (Supervisor) ; Sarbolouki, Mohammad Nabi (Supervisor)
Abstract
In the first part of this work, citric acid monomer was selected to produce dendrimer through the divergent method using logical conditions (for controlling its functional groups) on the base of poly (ethylene glycol) as the core. Triblock copolymers (ABA-type) of citric acid and poly (ethylene glycol) (PCA-PEG-PCA) as biocompatible compounds were synthesized in four different molecular weights and applied as nanocarriers. The structure definition of the molecules and nanoparticles were carried out using different spectroscopy methods. Diameter of the synthesized copolymers was investigated using dynamic light scattering (DLS) experiments and transmission electron microscopy (TEM) and it was...
Prediction of CO2 loading capacity of chemical absorbents using a multi-layer perceptron neural network
, Article Fluid Phase Equilibria ; Volume 354 , September , 2013 , Pages 6-11 ; 03783812 (ISSN) ; Hamzehie, M. E ; Davardoost, F ; Mazinani, S ; Poorbashiri, A ; Sharif University of Technology
2013
Abstract
A feed forward multi-layer perceptron neural network was developed to predict carbon dioxide loading capacity of chemical absorbents over wide ranges of temperature, pressure, and concentration based on the molecular weight of solution. To verify the suggested artificial neural network (ANN), regression analysis was conducted on the estimated and experimental values of CO2 solubility in various aqueous solutions. Furthermore, a comparison was performed between results of the proposed neural network and experimental data that were not previously used for network training, as well as a set of data for binary solutions. Comparison between the proposed multi-layer perceptron (MLP) network and...
Simultaneously synthesis and encapsulation of metallic nanoparticles using linear-dendritic block copolymers of poly (ethylene glycol)-poly (citric acid)
, Article Key Engineering Materials, 8 July 2010 through 9 July 2010 ; Volume 478 , July , 2011 , Pages 7-12 ; 10139826 (ISSN) ; 9783037851357 (ISBN) ; Vossoughi, M ; Adeli, M ; Sharif University of Technology
2011
Abstract
Linear-dendritic triblock copolymers of linear poly(ethylene glycol) and hyperbranched poly(citric acid) (PCA-PEG-PCA) were used as the reducing and capping agents to encapsulate gold and silver nanoparticles (AuNPs and AgNPs). PCA-PEG-PCA copolymers in four different molecular weights were synthesized using 2, 5, 10 and 20 citric acid/PEG molar ratios and were called A 1, A 2, A 3 and A 4, respectively. Nanoparticles were encapsulated simultaneously during the preparation process. AuNPs were simply synthesized and encapsulated by addition a boiling aqueous solution of HAuCl 4 to aqueous solutions of A 1, A 2, A 3 and A 4. In the case of silver, an aqueous solution of AgNO 3 was reduced...
Synthesis of gold nanoparticle necklaces using linear-dendritic copolymers
, Article European Polymer Journal ; Volume 46, Issue 2 , 2010 , Pages 165-170 ; 00143057 (ISSN) ; Adeli, M ; Vossoughi, M ; Sharif University of Technology
2010
Abstract
Linear-dendritic copolymers containing hyperbranched poly(citric acid) and linear poly(ethylene glycol) blocks (PCA-PEG-PCA) were used as reducing and capping agents to synthesize and support gold nanoparticles (AuNPs). PCA-PEG-PCA copolymers with 1758, 1889 and 3446 molecular weights, called A1, A2 and A3 through this work, respectively, were synthesized using 2, 5, and 10 citric acid/PEG molar ratios. The diameter of A1, A2 and A3 in a fresh water solution was investigated using dynamic light scattering (DLS) and it was between 1.8 and 2.8 nm. AuNPs were simply synthesized and supported by addition a boiling aqueous solution of HAuCl4 to aqueous solutions of A1, A2 and A3. Supported AuNPs...
Numerical Investigation of the Performance of Concrete Beamcolumns with FRP Bars under Concentric and Eccentric Loading and Four-Points Bending
, M.Sc. Thesis Sharif University of Technology ; Khaloo, Alireza (Supervisor)
Abstract
Glass Fiber Reinforced Polymer (GFRP) bars with significant corrosion resistance lead to an improvement in the performance of concrete structures and a significant reduction in costs. High ratio of tensile strength to weight, non-conductive, and non-magnetic properties are other features of GFRP bars. Recent international design standards, such as ACI 440.1R-15 do not recommend including FRP reinforcement in compression, so they replace them by concrete in calculations. The purpose of this study was to investigate the effect of concentric and excentric axial loading on the axial capacity and ductility of GFRP reinforced concrete columns compared to steel reinforced concrete columns,...
Evaluation of Vermifilter Efficiency in Petroleum Wastewater Treatment (BTEX)
, M.Sc. Thesis Sharif University of Technology ; Torkian, Ayub (Supervisor) ; Mirzai, Mohammad (Supervisor)
Abstract
The aim of this thesis was to find the optimum retention time for treatment of synthetic petroleum wastewater by a wastewater treatment system made with a bucket, mineral material and earthworms residing in a vermibed. In order to make the desired flow happen, height difference was utilized. The polluting substance used for making wastewater was BTEX. As the wastewater was synthetic, the concentration was also a variable. The ultimate soluble concentration was 3200 mg/l and more concentrations were not tested. Parameters such as number of worms, worm’s growth rate and their distribution pattern, humidity amount and distribution and worm’s acclimatization time during organic loading shock...
A new linguistic steganography scheme based on lexical substitution
, Article 2014 11th International ISC Conference on Information Security and Cryptology, ISCISC 2014 ; 2014 , pp. 155-160 ; ISBN: 9781479953837 ; Mousavi, A. S ; Amirmazlaghani, M ; Sharif University of Technology
Abstract
Recent studies in the field of text-steganography shows a promising future for linguistic driven stegosystems. One of the most common techniques in this field is known as lexical substitution which provides the requirements for security and payload capacity. However, the existing lexical substitution schemes need an enormous amount of shared data between sender and receiver which acts as the stego key. In this paper, we propose a novel encoding method to overcome this problem. Our proposed approach preserves the good properties of lexical substitution schemes while it provides short length stego keys and significant robustness against active adversary attacks. We demonstrate high efficiency...
A new set of codes with swift decoding for overloaded synchronous CDMA
, Article 22nd National Conference on Communication, 4 March 2016 through 6 March 2016 ; 2016 ; 9781509023615 (ISBN) ; Singh, P ; Amini, A ; Marvasti, F ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
Abstract
We consider the designing of a new set of uniquely decodable codes for uncoded synchronous overloaded CDMA system that exists for arbitrary values of spreading gain (code length). A fast and recursive method of construction is proposed where the orthogonal Hadamard matrix of least dimension (two), as the basis of construction regularizes a ternary pattern which is further leveraged to attain a rich simplicity in decoder design. The simplicity gained in designing of the proposed Comparison Aided Decoder (CAD) is prominent enough to neglect the marginal sacrifice in Bit Error Rate (BER) as compared to the optimum Maximum Likelihood Decoder (MLD) for noisy transmission. Despite its low complex...
Effect of fibers configuration and thickness on tensile behavior of GFRP laminates subjected to elevated temperatures
, Article Construction and Building Materials ; Volume 202 , 2019 , Pages 189-207 ; 09500618 (ISSN) ; Bazli, M ; Ashrafi, H ; Vatani Oskouei, A ; Azhari, S ; Zhao, X. L ; Gholipour, H ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
This study was aimed at gaining an improved understanding of the behavior of glass fiber-reinforced polymer laminates at elevated temperatures by means of testing laminate specimens with unidirectional, woven, and randomly distributed (chopped strand mat) fibers. The testing parameters were temperature, the type of fiber, and the thickness of the laminates. The failure modes of the specimens and their elasticity moduli at ambient temperature were investigated, and analysis of variance was conducted to determine the contribution of each parameter to the behavioral test results. The findings showed that among the parameters, an increase in temperature exerted the strongest effect on the...
Electrophoretic encapsulation for slow release of vancomycin from perpendicular TiO2 nanotubes grown on Ti6Al4V electrodes
, Article Materials Research Express ; Volume 6, Issue 12 , 2019 ; 20531591 (ISSN) ; https://iopscience.iop.org/article/10.1088/2053-1591/ab6c98 ; Ahmadi Seyedkhani, S ; Sadrnezhaad, S. K ; Sharif University of Technology
Institute of Physics Publishing
2019
Abstract
Ordered perpendicular TiO2 nanotubes (TNT) with 405 to 952 nm length and 60 to 90 nm diameter were grown via 40 to 120 min anodization of Ti6Al4V flat substrates. The samples were called TNT-40, -60, -80, -100, and -120. Vancomycin was loaded on the bare and anodized electrodes by separate immersion and electrophoretic (EP) deposition procedures. EP loading resulted in storage capacity of 5221.86 μg cm-2 for TNT-80 which was much higher than 1036.75 μg cm-2 of immersed sample. Drug release comprised of three stages: (i) burst release (78% for the bare, and 23% for the TNT-80 sample), (ii) gradual transport (21% for the bare, and 64% for the TNT-80 sample), and (iii) equilibrium. Transfer...
Electrophoretic encapsulation for slow release of vancomycin from perpendicular TiO2 nanotubes grown on Ti6Al4V electrodes
, Article Materials Research Express ; Volume 6, Issue 12 , 2019 ; 20531591 (ISSN) ; Ahmadi Seyedkhani, S ; Sadrnezhaad, S. K ; Sharif University of Technology
Institute of Physics Publishing
2019
Abstract
Ordered perpendicular TiO2 nanotubes (TNT) with 405 to 952 nm length and 60 to 90 nm diameter were grown via 40 to 120 min anodization of Ti6Al4V flat substrates. The samples were called TNT-40, -60, -80, -100, and -120. Vancomycin was loaded on the bare and anodized electrodes by separate immersion and electrophoretic (EP) deposition procedures. EP loading resulted in storage capacity of 5221.86 μg cm-2 for TNT-80 which was much higher than 1036.75 μg cm-2 of immersed sample. Drug release comprised of three stages: (i) burst release (78% for the bare, and 23% for the TNT-80 sample), (ii) gradual transport (21% for the bare, and 64% for the TNT-80 sample), and (iii) equilibrium. Transfer...
Synthesis of magnesium-based Janus micromotors capable of magnetic navigation and antibiotic drug incorporation
, Article New Journal of Chemistry ; Volume 44, Issue 17 , 2020 , Pages 6947-6957 ; Madaah Hosseini, H. R ; Abedini, F ; Dabbagh, A ; Sharif University of Technology
Royal Society of Chemistry
2020
Abstract
In the present study, bubble-driven magnesium-based micromotors were fabricated through a shading method, and the potential of magnetic guidance of magnesium-based Janus micro/nanomotors through functionalization with superparamagnetic iron oxide nanoparticles (SPIONs) was investigated for the first time. SPIONs had physical electrostatic attraction with the positively charged magnesium spheres due to negative charges on their surfaces. It was also found that upon applying a field gradient, the micromotors’ velocity increased by 13% unlike other magnetically navigated spherical magnesium-based micromotors which only show a change in direction. In this work the cytotoxicity of the moving...
Seismic behavior comparison of RC shear walls strengthened using FRP composites and steel elements
, Article Scientia Iranica ; Volume 28, Issue 3 A , 2021 , Pages 1-27 ; 10263098 (ISSN) ; Khaloo, A ; Abdoos, H ; Sharif University of Technology
Sharif University of Technology
2021
Abstract
This paper aims at investigating the seismic behavior of strengthened reinforced concrete (RC) shear walls using a 3D finite element analysis. A series of four different configurations of carbon fiber reinforced polymer (CFRP) composites and four different schemes of steel elements are utilized to compare the two methods of retrofitting RC shear walls with similar dimensions and reinforcement ratios. Nonlinear simulations of the RC shear walls are conducted under the action of lateral cyclic loading in ABAQUS Explicit software. In addition, the numerical modeling for RC walls strengthened by CFRP composites as well as steel elements are validated according to the previous experimental...
Optimization of geometric parameters of latticed structures using genetic algorithm
, Article Aircraft Engineering and Aerospace Technology ; Volume 83, Issue 2 , 2011 , Pages 59-68 ; 00022667 (ISSN) ; Kargarnovin, M. H ; Jam, J. E ; Sharif University of Technology
2011
Abstract
Purpose - The purpose of this paper is to analyze a squared lattice cylindrical shell under compressive axial load and to optimize the geometric parameters to achieve the maximum buckling load. Also a comparison between buckling loads of a squared lattice cylinder and a solid hollow cylinder with equal weight, length and outer diameter is performed to reveal the superior performance of the squared lattice cylindrical shells. Design/methodology/ approach - A cylindrical lattice shell includes circumferential and longitudinal rods with geometric parameters such as crosssection areas of the rods, distances and angles between them. In this study, the governing differential equation for buckling...
Behavior of channel shear connectors, Part I: Experimental study
, Article Journal of Constructional Steel Research ; Volume 64, Issue 12 , December , 2008 , Pages 1333-1340 ; 0143974X (ISSN) ; Bagheri, S ; Sharif University of Technology
2008
Abstract
In composite beams, shear connectors are commonly used to transfer longitudinal shear forces across the steel-concrete interface. This paper presents an experimental study on the behavior of channel shear connectors embedded in a solid concrete material slab under monotonic and low-cycle fatigue loading. The latter would be applicable to composite structures subjected to seismic events. Of specific interest are the behavior and effects of different concrete materials. A series of push-out specimens made of plain concrete, reinforced concrete (RC), fiber reinforced concrete (FRC) and engineered cementitious composite (ECC) were tested for this evaluation. The results show that the reversed...
Nonlinear analysis of masonry-infilled steel frames with openings using discrete element method
, Article Journal of Constructional Steel Research ; Volume 64, Issue 12 , 2008 , Pages 1463-1472 ; 0143974X (ISSN) ; Tasnimi, A. A ; Moghadam, H. A ; Sharif University of Technology
2008
Abstract
Nonlinear numerical modeling of masonry-infilled frames is one of the most complicated problems in structural engineering field. This complexity is attributed to the existence of joints as the major source of weakness and material nonlinearities as well as the infill-frame interaction which cannot be properly modeled using the traditional finite element methods. Although there are many numerical studies available on solid masonry-infilled steel frames' behavior, however, few researches have been conducted on infilled frames with openings. In this paper a two-dimensional numerical model using the specialized discrete element method (DEM) software UDEC (2004) is developed for the nonlinear...