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A magnetic multifunctional dendrimeric coating on a steel fiber for solid phase microextraction of chlorophenols
, Article Microchimica Acta ; Volume 184, Issue 7 , 2017 , Pages 2201-2209 ; 00263672 (ISSN) ; Manouchehri, M ; Allahdadlalouni, M ; Sharif University of Technology
Springer-Verlag Wien
2017
Abstract
A polyamidoamine dendrimer was synthesized, placed on magnetite nanoparticles, and the resulting material was then employed as a fiber coating for use in solid phase microextraction of chlorophenols. The polyamidoamine was expected to be an efficient extracting medium due to the presence of multipolar groups and its inner porosity. A thin stainless steel wire was coated with the dendritic polyamidoamine polymer via electrolysis and chemical reactions. The coated fiber was investigated in terms of headspace solid phase microextraction of chlorophenols from aqueous samples followed by GC-MS quantitation. The calibration plots are linear in the 2–1000 ng⋅L−1 chlorophenol concentration ranges....
A piezoelectric medium containing a cylindrical inhomogeneity: Role of electric capacitors and mechanical imperfections
, Article International Journal of Solids and Structures ; Volume 44, Issue 20 , 2007 , Pages 6361-6381 ; 00207683 (ISSN) ; Tabatabaei, S. M ; Kamali, M. T ; Sharif University of Technology
2007
Abstract
Often, during fabrication processes of fiber-matrix composites, the pertinent interface may be made imperfectly bonded either deliberately or undesirably. The effect of electric capacitors and mechanical imperfections on the electro-mechanical fields associated with an anisotropic piezoelectric matrix containing a cylindrical inhomogeneity made of a different anisotropic piezoelectric material is of interest. In fact the interface imperfection condition presented in this paper is quite general, in the sense that any combination of mechanical and electrical imperfections may exist. The interface electrical imperfection is mimicked by the electric capacitors. The capacity of the capacitors is...
Investigation of Amyloid-Beta Inhibition using Multifunctional Peptide Drugs Associated with Metal Ions
, Ph.D. Dissertation Sharif University of Technology ; Shamloo, Amir (Supervisor)
Abstract
Many experimental and theoretical studies have suggested that zinc binding to Aβ could promote amyloid-β aggregation and reactive oxygen species (ROS) production induced by AD disease. Therefore, the introduction of multifunctional drugs capable of chelating zinc metal ion and inhibiting Aβ aggregation is a promising strategy in the development of AD treatment. In present study molecular docking and molecular dynamics (MD) simulations were used to evaluate the efficacy of two new bifunctional peptide drug, composed of two different domains: C-terminal hydrophobic region of Aβ and Zn2+ chelator region. To evaluate the multifunctionality of the ligands, a comprehensive set of MD simulations up...
Dendritic magnetite decorated by pH-responsive PEGylated starch: A smart multifunctional nanocarrier for the triggered release of anti-cancer drugs
, Article RSC Advances ; Volume 5, Issue 60 , Jun , 2015 , Pages 48586-48595 ; 20462069 (ISSN) ; Mazaheri Tehrani, Z ; Hosseini, S. H ; Sharif University of Technology
Royal Society of Chemistry
2015
Abstract
In the present study, we designed a pH-responsive drug nanocarrier based on polyamidoamine-modified Fe3 O4 nanoparticles coated by PEGylated starch-co-poly(acrylic acid). This carrier was used for the controlled release of doxorubicin as an anticancer drug model. The purpose of using the polyethylene glycol moiety is to generate a biostable nanocarrier in blood stream as it has been reported widely in the pharmaceutical literature. The use of a poly(acrylic acid) segment also provided pH-sensitivity to the polymer. Besides, the magnetic nanoparticles facilitate the cancer cell targeting with an external magnetic field located near the tumor site. This carrier was...
Effective shear modulus of solids reinforced by randomly oriented-/aligned-elliptic nanofibers in couple stress elasticity
, Article Composites Part B: Engineering ; Volume 117 , 2017 , Pages 150-164 ; 13598368 (ISSN) ; Alemi, B ; Sharif University of Technology
Abstract
Nowadays, by adding a small amount (about 0.5–5% by weight) of a desired nanomaterial to a matrix having certain properties one may design a multifunctional nanocomposites with a remarkably improved macroscopic properties of interest. The capability of conventional continuum theories in treating the problems of embedded ultra-small inhomogeneity with any of its dimensions comparable to the characteristic lengths of the involved constituent phases is questioned, mainly, on the grounds of the accuracy and the size effect. The micromechanical framework based on the Eshelby's ellipsoidal inclusion theory [1] which has been widely used to estimate the overall behavior of composites falls under...
Polymer/nanodiamond composites - a comprehensive review from synthesis and fabrication to properties and applications
, Article Advances in Colloid and Interface Science ; Volume 269 , 2019 , Pages 122-151 ; 00018686 (ISSN) ; Salkhi Khasraghi, S ; Hashemi, M ; Rabiei, S ; Shojaei, A ; Sharif University of Technology
Elsevier B.V
2019
Abstract
Nanodiamond (ND)is an allotrope of carbon nanomaterials which exhibits many outstanding physical, mechanical, thermal, optical and biocompatibility characteristics. Meanwhile, ND particles possess unique spherical shape containing diamond-like structure at the core with graphitic carbon outer shell which intuitively contains many oxygen-containing functional groups at the outer surface. Such superior properties and unique structural morphology of NDs are essentially attractive to develop polymer composites with multifunctional properties. However, despite a long history from the discovery of NDs, which is dated back to the1960s, this nanoparticle has been less explored in the field of...
Highly biocompatible multifunctional hybrid nanoparticles based on Fe3O4 decorated nanodiamond with superior superparamagnetic behaviors and photoluminescent properties
, Article Materials Science and Engineering C ; Volume 114 , September , 2020 ; Shojaei, A ; Sundararaj, U ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
The multifunctional nanostructures with superparamagnetic and luminescent properties undergo revolution in the field of bio-nanotechnology. In this article, we reported a facile and efficient one-step modified co-precipitation method to load superparamagnetic Fe3O4 nanoparticle on oxidized nanodiamond (Ox-ND). Subsequently, the as-prepared Ox-ND/Fe3O4 hybrid nanoparticle was surface functionalized with vinyltrimethoxysilane (VTMS) to enhance its compatibility with organic media. The structure, morphology, magnetic, and optical properties of the nanohybrid were systematically investigated. The results confirmed successful loading of crystalline Fe3O4 on the surface of Ox-ND. Ox-ND/Fe3O4...
Bioactive Nanocomposite Coatings Containing Anti-Bacterial Factors with Controlled Release on the Bone Implant
, Ph.D. Dissertation Sharif University of Technology ; Ghorbani, Mohammad (Supervisor) ; Shokrgozar, Mohammad Ali (Supervisor) ; Pooshang Bagheri, Kamran (Co-Supervisor)
Abstract
Aseptic loosening and infection are two major problems of bone implants. Aseptic loosening occurs due to poor cell growth and poor adhesion to the implant surface over time. Bone infection at the implant site occurs mainly by the staphylococcus aureus bacteria. In some cases, infection occurs in the short term and in the early times after implantation, and in some cases, infection occurs in later times. The aim of this study is to synthesize and evaluate antibacterial coatings, while having cell growth-promoting components and cell differentiation to solve bone implant problems simultaneously. Also, the issue of bacterial resistance to antibiotics and their risks in bone implants is another...
New considerations in modern protection system quantitative reliability assessment
, Article IEEE Transactions on Power Delivery ; Vol. 25, issue. 4 , 2010 , p. 2213-2222 ; ISSN: 8858977 ; Fotuhi-Firuzabad, M ; Sharif University of Technology
Abstract
Protective relay technologies have evolved from single-function electromechanical and static relays to modern multifunction digital relays over the past few years. Protection systems play a vital role in maintaining a desirable level of reliability in power systems. Thus, their own reliability should be evaluated and any cause of their malfunction should be fully comprehended. In this paper, a new reliability model is proposed that associates protection system failures to four main causes: 1) relay hardware, 2) relay software, 3) ancillary equipment, and 4) human error. In addition, this model can take other aspects of the protection system into consideration, such as human error during...
New considerations in modern protection system quantitative reliability assessment
, Article IEEE Transactions on Power Delivery ; Volume 25, Issue 4 , September , 2010 , Pages 2213-2222 ; 08858977 (ISSN) ; Fotuhi Firuzabad, M ; Sharif University of Technology
2010
Abstract
Protective relay technologies have evolved from single-function electromechanical and static relays to modern multifunction digital relays over the past few years. Protection systems play a vital role in maintaining a desirable level of reliability in power systems. Thus, their own reliability should be evaluated and any cause of their malfunction should be fully comprehended. In this paper, a new reliability model is proposed that associates protection system failures to four main causes: 1) relay hardware, 2) relay software, 3) ancillary equipment, and 4) human error. In addition, this model can take other aspects of the protection system into consideration, such as human error during...
Green synthesis of ternary carbon dots (CDs)/MIL-88B (Fe)/Bi2S3 nanocomposite via MOF templating as a reusable heterogeneous nanocatalyst and nano-photocatalyst
, Article Materials Research Bulletin ; Volume 138 , 2021 ; 00255408 (ISSN) ; Shahsavari, S ; Gholami, M.R ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
An environmentally friendly heterogeneous ternary carbon dots (CDs)/MIL-88B (Fe)/Bi2S3 nanocomposite was synthesized by a multistep method. In this study, we have studied low-temperature calcination with relatively inexpensive reactants. The sufficient CD arrays were generated by loading the glucose molecules into the pores of an as-obtained metal-organic framework (MOF), i.e. MIL-88B (Fe)), by heating to 200 °C. Fabricated nanocomposite structures were characterized by FT-IR, XRD, EIS, SEM, TEM, BET, and TGA techniques, demonstrating the decoration of the Bi2S3 on the CDs/MIL-88B (Fe) nanocomposite surface. MOF templating has been chosen as a systemic method for limited size CD formation...
The effect of Ag incorporation on the characteristics of the polymer derived bioactive silicate phosphate glass-ceramic scaffolds
, Article Boletin de la Sociedad Espanola de Ceramica y Vidrio ; 2021 ; 03663175 (ISSN) ; Godary, T ; Khalilifard, R ; Malek Khachatourian, A ; Abdollahi, F ; Abdollahi, S ; Sharif University of Technology
Sociedad Espanola de Ceramica y Vidrio
2021
Abstract
In the bone tissue engineering field (BTE), it is of significant importance to develop bioactive multifunctional scaffolds with enhanced osteoconductivity, osteoinductivity, and antibacterial properties required for lost bone tissue regeneration. In this work, a bioactive glass-ceramic scaffold was manufactured via a novel polymer-derived ceramics (PDC) manufacturing method. To gain antibacterial properties, the silver ions were incorporated in controlled amount along with other precursors in the PDC processing stage. Microstructural and structural properties of the fabricated silicate-phosphate glass-ceramic scaffold were evaluated by scanning electron microscopy (SEM) equipped with energy...
Evaluating the multifunctionality of a new modulator of zinc-induced Aβ aggregation using a novel computational approach
, Article Journal of Chemical Information and Modeling ; Volume 61, Issue 3 , 2021 , Pages 1383-1401 ; 15499596 (ISSN) ; Shamloo, A ; Sharif University of Technology
American Chemical Society
2021
Abstract
The high concentration of zinc metal ions in Aβ aggregations is one of the most cited hallmarks of Alzheimer's disease (AD), and several substantial pieces of evidence emphasize the key role of zinc metal ions in the pathogenesis of AD. In this study, while designing a multifunctional peptide for simultaneous targeting Aβ aggregation and chelating the zinc metal ion, a novel and comprehensive approach is introduced for evaluating the multifunctionality of a multifunctional drugs based on computational methods. The multifunctional peptide consists of inhibitor and chelator domains, which are included in the C-terminal hydrophobic region of Aβ, and the first four amino acids of human albumin....
Enzyme-inspired lysine-modified carbon quantum dots performing carbonylation using urea and a cascade reaction for synthesizing 2-benzoxazolinone
, Article ACS Catalysis ; Volume 11, Issue 17 , 2021 , Pages 10778-10788 ; 21555435 (ISSN) ; Kalhor, H. R ; Sharif University of Technology
American Chemical Society
2021
Abstract
Catalysts as the dynamo of chemical reactions along with solvents play paramount roles in organic transformations in long-lasting modes. Thus, developing effective and biobased catalysts in nontoxic solvents is highly in demand. In this report, carbon quantum dots (CQDs) functionalized with-lysine (Lys-CQDs) were generated from entirely nature-derived materials; they were demonstrated to be a promising catalyst for C-N bond formation in choline chloride urea (ChCl/U), a natural deep eutectic solvent (NADES). Among a number of synthesized CQDs, Lys-CQD turned out to be a powerful catalyst in the model reaction with aniline to afford phenyl urea. This type of transformation is important...
Carboxymethyl cellulose-based functional film integrated with chitosan-based carbon quantum dots for active food packaging applications
, Article Progress in Organic Coatings ; Volume 166 , 2022 ; 03009440 (ISSN) ; Rhim, J. W ; Bagheri, R ; Pircheraghi, G ; Lotfali, E ; Sharif University of Technology
Elsevier B.V
2022
Abstract
A chitosan-based carbon quantum dots (CQDs) with multifunctional properties were synthesized using a hydrothermal process. The CQDs were spherical with an average size of 7.8 ± 2.4 nm. The CQD showed strong antioxidant activity, potent antibacterial activity against E. coli and L. monocytogenes, and antifungal activity against A. niger and P. chrysogenum. In addition, the prepared CQD showed negligible cytotoxicity against L929 cells even at a concentration of 500 μg/mL. Carboxymethyl cellulose (CMC)-based functional films were fabricated by adding various amounts of CQD. The CQDs were evenly dispersed in the polymer matrix to form a highly transparent UV-blocking film. The addition of CQD...
A facile, two-step synthesis and characterization of Fe3 O4–LCysteine–graphene quantum dots as a multifunctional nanocomposite
, Article Applied Nanoscience (Switzerland) ; Volume 11, Issue 3 , 2021 , Pages 849-860 ; 21905509 (ISSN) ; Madaah Hosseini, H. R ; Sharif University of Technology
Springer Science and Business Media Deutschland GmbH
2021
Abstract
In this research, a facile, two-step synthesis of Fe3O4–LCysteine–graphene quantum dots (GQDs) nanocomposite is reported. This synthesis method comprises the preparation of GQDs via hydrothermal route, which should be conjugated to the LCysteine functionalized core–shell magnetic structure with the core of about 7.5-nm iron oxide nanoparticle and 3.5-nm LCysteine shell. LCysteine, as a biocompatible natural amino acid, was used to link magnetite nanoparticles (MNPs) with GQDs. X-ray powder diffraction, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, energy dispersive X-ray were used to investigate the presence and formation of MNPs, L Cysteine functionalized MNPs,...
A facile, two-step synthesis and characterization of Fe3 O4–LCysteine–graphene quantum dots as a multifunctional nanocomposite
, Article Applied Nanoscience (Switzerland) ; Volume 11, Issue 3 , 2021 , Pages 849-860 ; 21905509 (ISSN) ; Madaah Hosseini, H. R ; Sharif University of Technology
Springer Science and Business Media Deutschland GmbH
2021
Abstract
In this research, a facile, two-step synthesis of Fe3O4–LCysteine–graphene quantum dots (GQDs) nanocomposite is reported. This synthesis method comprises the preparation of GQDs via hydrothermal route, which should be conjugated to the LCysteine functionalized core–shell magnetic structure with the core of about 7.5-nm iron oxide nanoparticle and 3.5-nm LCysteine shell. LCysteine, as a biocompatible natural amino acid, was used to link magnetite nanoparticles (MNPs) with GQDs. X-ray powder diffraction, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, energy dispersive X-ray were used to investigate the presence and formation of MNPs, L Cysteine functionalized MNPs,...