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    Amino acid ionic liquids based on imidazolium-hydroxyl functionalized cation: New insight from molecular dynamics simulations

    , Article Journal of Molecular Liquids ; Volume 279 , 2019 , Pages 51-62 ; 01677322 (ISSN) Fakhraee, M ; Sharif University of Technology
    Elsevier B.V  2019
    Various thermodynamic and structural properties of amino acid ionic liquids (AAILs), comprising 1-(2-Hydroxyethyl)-3-methyl imidazolium ([C 2 OHmim] + ) cation mixed with Glycinate [Gly], Serinate [Ser], Alaninate [Ala], and Prolinate [Pro] AA anions are explored using molecular dynamic (MD) simulations and quantum theory of atoms in molecules (QTAIM) analysis. In general, the simulated thermodynamic results are in good agreement with the reported experimental data. Structural dependence of vdW- and electrostatic energies of AAILs is [Pro] > [Ala] > [Ser] > [Gly] and [Gly] > [Ala] > [Pro] > [Ser], respectively. The similar trend of electrostatic energies is found for their interaction... 

    Interaction of water-soluble amino acid Schiff base complexes with bovine serum albumin: Fluorescence and circular dichroism studies

    , Article Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy ; Volume 71, Issue 4 , 2008 , Pages 1617-1622 ; 13861425 (ISSN) Gharagozlou, M ; Mohammadi Boghaei, D ; Sharif University of Technology
    Fluorescence spectroscopy in combination with circular dichroism (CD) spectroscopy were used to investigate the interaction of water-soluble amino acid Schiff base complexes, [Zn(L1,2)(phen)] where phen is 1,10-phenanthroline and H2L1,2 is amino acid Schiff base ligands, with bovine serum albumin (BSA) under the physiological conditions in phosphate buffer solution adjusted to pH 7.0. The quenching mechanism of fluorescence was suggested as static quenching according to the Stern-Volmer equation. Quenching constants were determined using the Stern-Volmer equation to provide a measure of the binding affinity between amino acid Schiff base complexes and BSA. The thermodynamic parameters ΔG, ΔH... 

    Spectral characterization of novel ternary zinc(II) complexes containing 1,10-phenanthroline and schiff bases derived from amino acids and salicylaldehyde-5-sulfonates

    , Article Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy ; Volume 67, Issue 3-4 , 2007 , Pages 944-949 ; 13861425 (ISSN) Boghaei, D. M ; Gharagozlou, M ; Sharif University of Technology
    A series of new ternary zinc(II) complexes [Zn(L1-10)(phen)], where phen is 1,10-phenanthroline and H2L1-10 = tridentate Schiff base ligands derived from the condensation of amino acids (glycine, l-phenylalanine, l-valine, l-alanine, and l-leucine) and salicylaldehyde-5-sulfonates (sodium salicylaldehyde-5-sulfonate and sodium 3-methoxy-salicylaldehyde-5-sulfonate), have been synthesized. The complexes were characterized by elemental analysis, IR, UV-vis, 1H NMR, and 13C NMR spectra. The IR spectra of the complexes showed large differences between νas(COO) and νs(COO), Δν (νas(COO) - νs(COO)) of 191-225 cm-1, indicating a monodentate coordination of the carboxylate group. Spectral data... 

    Radial basis function-artificial neural network (RBF-ANN) for simultaneous fluorescent determination of cysteine enantiomers in mixtures

    , Article Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy ; Volume 261 , 2021 ; 13861425 (ISSN) Safarnejad, A ; Reza Hormozi Nezhad, M ; Abdollahi, H ; Sharif University of Technology
    Elsevier B.V  2021
    The determination of chiral compounds is critically important in chemical and pharmaceutical sciences. Cysteine amino acid is one of the important chiral compounds where each enantiomer (L and D) has different effects on fundamental physiological processes. The unique optical properties of nanoparticles make them a suitable probe for the determination of different analytes. In this work, the water-soluble thioglycolic acid (TGA)-capped cadmium-telluride (CdTe) quantum dots (QDs) were applied as optical nanoprobe for the simultaneous determination of cysteine enantiomers. The difference in the kinetics of the interactions between L- and D-cysteine with CdTe QDs is used for multivariate... 

    Protein G selects two binding sites for carbon nanotube with dissimilar behavior; a molecular dynamics study

    , Article Journal of Molecular Graphics and Modelling ; Volume 87 , 2019 , Pages 257-267 ; 10933263 (ISSN) Ebrahim Habibi, M. B ; Ghobeh, M ; Aghakhani Mahyari, F ; Rafii Tabar, H ; Sasanpour, P ; Sharif University of Technology
    Elsevier Inc  2019
    Background: Study of nanostructure-protein interaction for development of various types of nano-devices is very essential. Among carbon nanostructures, carbon nanotube (CNT) provides a suitable platform for functionalization by proteins. Previous studies have confirmed that the CNT induces changes in the protein structure. Methods: Molecular dynamics (MD) simulation study was employed to illustrate the changes occurring in the protein G (PGB) in the presence of a CNT. In order to predict the PGB surface patches for the CNT, Autodock tools were utilized. Results: Docking results indicate the presence of two different surface patches with diverse amino acids: the dominant polar residues in the... 

    Degradation of BTEX in groundwater by nano-CaO2 particles activated with L-cysteine chelated Fe(III): enhancing or inhibiting hydroxyl radical generation

    , Article Water Supply ; Volume 21, Issue 8 , 2021 , Pages 4429-4441 ; 16069749 (ISSN) Sun, X ; Ali, M ; Cui, C ; Lyu, S ; Sharif University of Technology
    IWA Publishing  2021
    The simultaneous oxidation performance of benzene, toluene, ethylbenzene, and xylene (BTEX) by nanoscale calcium peroxide particles (nCaO2) activated with ferric ions (Fe(III)) and the mechanism of the enhancement of BTEX degradation by L-cysteine (L-cys) were investigated. The batch experimental results showed that the nCaO2/Fe(III)/L-cys process was effective in the destruction of BTEX in both ultrapure water and actual groundwater. A proper amount of L-cys could enhance BTEX degradation due to the promotion of Fe(II)/Fe(III) redox cycles by the participation of L-cys, but an excessive presence of L-cys would cause inhibition. Adding 1.0 mM L-cys to the nCaO2/Fe(III) system, the... 

    Preparation of Thin-Film Nanocomposite Membranes Based on Metal-Organic Frameworks (Mofs) and Study of their Performance in Forward Osmosis (Fo) Process

    , Ph.D. Dissertation Sharif University of Technology Bayrami, Arshad (Author) ; Bagherzadeh, Mojtaba (Supervisor)
    The forward osmosis (FO) process is a high potential emerging membrane process in the seawater desalination and contaminated water treatment fields. One of the main challenges facing this process is the weak separation (high reverse solute flux, low water flux, and insufficient selectivity) and antifouling performances of its membranes. Various sections of this study focus on the development of FO membranes and their performance improvement. For this purpose, thin-film composite membranes with the same combination of polyethersulfone/polyamide (PES/PA) have been used to investigate the effect of metal-organic frameworks (MOFs) introduction on their performance. The support layer in all cases... 

    Stability of binary and ternary copper (II) complexes of 2((4-methyl-5-nitro-6-(pyrrolidine-l-yl)pyrimidine-2-yl) amino) propionic acid in aqueous solution

    , Article Scientia Iranica ; Vol. 21, Issue. 6 , 2014 , pp. 2029-2035 ; ISSN: 10263098 Sajadi, S. A. A ; Bagherzadeh, G ; Khaleghian, M ; Kermani, M ; Sharif University of Technology
    The acidity and stability constants of M (MNPPAP) (MNPPAP: 2((4-methyl-5-nitro-6-(pyrrolidine-l-yl)pyrimidine-2-yl)amino)propionic acid) M: Cu2+, Cu (Bpy)2+ (Bpy: 2,2'-Bipyridine), or Cu(Phen) (Phen: 1,10-Phenanthroline) complexes were determined by potentiometric pH titration. It is shown that the stability of the binary Cu (MNPPAP) complex is determined by the basicity of the carboxylate group on one side and amine group on the other side. It is demonstrated that the equilibrium, Cu(Har)2+ (H ar: Heteroaromatic ligand such as Bpy or Phen) + Cu(MNPPAP) ^ Cu(Har)(MNPPAP) + Cu2+, is displacement due to the well known experience that mixed ligand complexes formed by a divalent 3d ion, a... 

    Rapid and simultaneous determination of tetracycline and cefixime antibiotics by mean of gold nanoparticles-screen printed gold electrode and chemometrics tools

    , Article Measurement: Journal of the International Measurement Confederation ; Vol. 47, Issue. 1 , 2014 , pp. 145-149 ; ISSN: 02632241 Asadollahi-Baboli, M ; Mani-Varnosfaderani, A ; Sharif University of Technology
    The screen-printed gold electrode (SPGE) modified with the formation of self-assembly monolayer (SAM) of cysteine (Cys) on gold-nanoparticles (Au nano) was utilized for rapid and simultaneous determination of tetracycline and cefixime antibiotics by square wave voltammetry (SWV). Electrochemical investigation and characterization of the modified electrode was achieved using cyclic voltammetry (CV) and scanning electron microscopy (SEM). A principal component artificial neural network (PCANN) with three layer back-propagation network was utilized for the analysis of the voltammogram data. It is possible to simultaneously determine the tetracycline and cefixime concentrations in the ranges of... 

    Useful multivariate kinetic analysis: Size determination based on cystein-induced aggregation of gold nanoparticles

    , Article Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy ; Volume 115 , 2013 , Pages 588-594 ; 13861425 (ISSN) Rabbani, F ; Nezhad, M. R. H ; Abdollahi, H ; Sharif University of Technology
    This study describes spectrometric monitored kinetic processes to determine the size of citrate-capped Au nanoparticles (Au NPs) based on aggregation induced by L-cysteine (L-Cys) as a molecular linker. The Au NPs association process is thoroughly dependent on pH, concentration and size of nanoparticles. Size dependency of aggregation inspirits to determine the average diameters of Au NPs. For this aim the procedure is achieved in aqueous medium at pH 7 (phosphate buffer), and multivariate data including kinetic spectra of Au NPs are collected during aggregation process. Subsequently partial least squares (PLS) modeling is carried out analyzing the obtained data. The model is built on the... 

    NMR based metabonomics study on celiac disease in the blood serum

    , Article Gastroenterology and Hepatology from Bed to Bench ; Volume 6, Issue 4 , 2013 , Pages 190-194 ; 20082258 (ISSN) Fathi, F ; Ektefa, F ; Arefi Oskouie, A ; Rostami, K ; Rezaei Tavirani, M ; Mohammad Alizadeh, A. H ; Tafazzoli, M ; Rostami Nejad, M ; Sharif University of Technology
    Aim: The aim of this study is to look for the proper methods that would be a major step towards untreated CD diagnosis and seek the metabolic biomarkers causes of CD and compare them to control group. Background: Celiac disease (CD) is a common autoimmune disorder that is not easily diagnosed using the clinical tests. Patients and methods: Thirty cases and 30 controls were entered into this study. Metabolic profiling was obtained using proton nuclear magnetic resonance spectroscopy (1HNMR) to seek metabolites that are helpful for the detection of CD. Classification of CD and healthy subject was done using random forest (RF). Results: The obtained classification model showed an 89% correct... 

    Interactions of coinage metal clusters with histidine and their effects on histidine acidity; Theoretical investigation

    , Article Organic and Biomolecular Chemistry ; Volume 10, Issue 47 , Oct , 2012 , Pages 9373-9382 ; 14770520 (ISSN) Javan, M. J ; Jamshidi, Z ; Tehrani, Z. A ; Fattahi, A ; Sharif University of Technology
    Understanding the nature of interaction between metal nanoparticles and biomolecules such as amino acids is important in the development and design of biosensors. In this paper, binding of M3 clusters (M = Au, Ag and Cu) with neutral and anionic forms of histidine amino acid was studied using density functional theory (DFT-B3LYP). It was found that the interaction of histidine with M3 clusters is governed by two major bonding factors: (a) the anchoring N-M and O-M bonds and (b) the nonconventional N-H⋯M and O-H⋯M hydrogen bonds. The nature of these chemical bonds has been investigated based on quantum theory of atoms in molecules (QTAIM) and natural bond orbital (NBO) analyses. In the next... 

    Nontoxic concentrations of PEGylated graphene nanoribbons for selective cancer cell imaging and photothermal therapy

    , Article Journal of Materials Chemistry ; Volume 22, Issue 38 , 2012 , Pages 20626-20633 ; 09599428 (ISSN) Akhavan, O ; Ghaderi, E ; Emamy, H ; Sharif University of Technology
    Reduced graphene oxide nanoribbons functionalized by amphiphilic polyethylene glycol (rGONR-PEG) were applied to attach arginine-glycine-aspartic acid (RGD)-based peptide and cyanine dye 3 (cy3) for targeting ανβ3 integrin receptors on human glioblastoma cell line U87MG and its selective fluorescence imaging, respectively. The rGONR-PEG suspension with a concentration of 100 μg mL -1 showed ∼14 and 2.4-fold higher near infrared (NIR) absorption at 808 nm than GONR (with dimensions of ∼80 nm × 1 μm) and rGO-PEG sheets (with lateral dimensions of ∼2 μm), respectively. The rGONR-PEG-cy3-RGD exhibited highly efficient NIR photothermal therapy performance (concentrations ≥1.0 μg mL-1 resulted in... 

    Spectrophotometric determination of glutathione and cysteine based on aggregation of colloidal gold nanoparticles

    , Article Scientia Iranica ; Volume 19, Issue 3 , June , 2012 , Pages 958-963 ; 10263098 (ISSN) Hormozi Nezhad, M. R ; Seyedhosseini, E ; Robatjazi, H ; Sharif University of Technology
    We report herein the development of a highly sensitive colorimetric method for the determination of cysteine and glutathione, based on aggregation of the citrate capped gold nanoparticles (Au NPs). This was exploited from high affinity of low-molecular-weight aminothiols towards the Au NPs surface, which could induce displacement of the citrate shell by the thiolate shell of target molecules, resulting in aggregation of the NPs through intermolecular electrostatic interaction or hydrogen-bonding. As a result of aggregation, which can be affected by the ionic strength, pH and concentration of Au NPs, the plasmon band at around 521 nm decreases gradually, along with formation of a new red... 

    Interactions of glutathione tripeptide with gold cluster: Influence of intramolecular hydrogen bond on complexation behavior

    , Article Journal of Physical Chemistry A ; Volume 116, Issue 17 , 2012 , Pages 4338-4347 ; 10895639 (ISSN) Tehrani, Z. A ; Jamshidi, Z ; Javan, M. J ; Fattahi, A ; Sharif University of Technology
    Understanding the nature of the interaction between metal nanoparticles and biomolecules has been important in the development and design of sensors. In this paper, structural, electronic, and bonding properties of the neutral and anionic forms of glutathione tripeptide (GSH) complexes with a Au 3 cluster were studied using the DFT-B3LYP with 6-31+G**-LANL2DZ mixed basis set. Binding of glutathione with the gold cluster is governed by two different kinds of interactions: Auâ€"X (X = N, O, and S) anchoring bond and Au··•·•H-X nonconventional hydrogen bonding. The influence of the intramolecular hydrogen bonding of glutathione on the interaction of this peptide with the gold cluster has been... 

    Synthesis and characterization of Ce-TZP/Al 2O 3 nanocomposites prepared via aqueous combustion

    , Article Journal of Alloys and Compounds ; Volume 514 , February , 2012 , Pages 150-156 ; 09258388 (ISSN) Asadirad, M ; Yoozbashizadeh, H ; Sharif University of Technology
    Nanocomposites of Ce-TZP/Al 2O 3 were synthesized by aqueous combustion, and urea, ammonium acetate and glycine were used as mixtures of fuels with the corresponding metal nitrates. Thermodynamic modeling was conducted to anticipate the effect of the alumina content on the exothermicity of the combustion procedure. The thermodynamic properties of the combustion reaction indicated that as the alumina content increased, the amount of gases produced during the reaction increased with a decrease in the adiabatic temperature. Furthermore, to reduce the particle size of the powders, a series of combustion reactions were performed to optimize the fuel composition and alumina content. Ce 0.1Zr 0.9O... 

    Ultrasonic-assisted synthesis of magnetite based MRI contrast agent using cysteine as the biocapping coating

    , Article Materials Chemistry and Physics ; Volume 131, Issue 1-2 , 2011 , Pages 170-177 ; 02540584 (ISSN) Ahmadi, R ; Malek, M ; Hosseini, H. R. M ; Shokrgozar, M. A ; Oghabian, M. A ; Masoudi, A ; Gu, N ; Zhang, Y ; Sharif University of Technology
    Magnetite nanoparticles (mean particle size ranging from 10 to 20 nm) were prepared by a biomoleculeassisted solution-phase approach under ultrasonic irradiation. Cysteine was used as the capping agent in the solution. The results show that cysteine could be an efficient biocapping agent in producing Fe3O4 nanoparticles. The crystal structure and magnetic properties of the nanoparticles were characterized by XRD and VSM techniques, respectively. FT-IR was used to investigate the presence of cysteine on the nanoparticles surface. The influence of pH value of the solution on the size distribution and hydrodynamic size of nanoparticles were studied by TEM and DLS methods, respectively. The MTT... 

    The effect of cysteine on electrodeposition of gold nanoparticle

    , Article Materials Science and Engineering B: Solid-State Materials for Advanced Technology ; Volume 176, Issue 16 , 2011 , Pages 1307-1312 ; 09215107 (ISSN) Dolati, A ; Imanieh, I ; Salehi, F ; Farahani, M ; Sharif University of Technology
    The most applications of gold nanoparticles are in the photo-electronical accessories and bio-chemical sensors. Chloride solution with cysteine additive was used as electrolyte in gold nanoparticles electrodeposition. The nucleation and growing mechanism were studied by electrochemical techniques such as cyclic voltammetry and chronoamperometry, in order to obtain a suitable nano structure. The deposition mechanism was determined as instantaneous nucleation and the dimension of particles was controlled in nanometric particle size range. Atomic Force Microscope was used to evaluate the effect of cysteine on the morphology and topography of gold nanoparticles. Finally the catalytic property of... 

    RETRACTED ARTICLE: Study of stabilities of L-cysteine and L-methionine with divalent metal ions: A comparison of thermodynamic data

    , Article 5th International Conference on Bioinformatics and Biomedical Engineering, iCBBE 2011 ; 2011 ; 9781424450893 (ISBN) Sajadi, S. A. A ; Sharif University of Technology
    The acidity and stability constants of M-Met (M: M2+; Met 1: L-methionine) complexes, determined by potentiometric pH titrations, were used to make a comparative investigation with L-cysteine (Cys). It is shown that regarding to M ion - binding properties vital differences on complex bilding were considered. It is demonstrated, that in M-Met complexes, M ion is coordinated to the carboxyl group, M ion is also able to build macrochelate over amine group. The upmentioned results demonstrate that for M-Met complex the stability constants is also largly determined by the affinity of Cu2+ for amino group but in opposite to Met, some metal ions such as Co2+, Cu2+, and Zn2+ build with Cys 2... 

    Influence of Substrate, Additives, and Pulse Parameters on Electrodeposition of Gold Nanoparticles from Potassium Dicyanoaurate

    , Article Metallurgical and Materials Transactions B: Process Metallurgy and Materials Processing Science ; Volume 46, Issue 6 , December , 2015 , Pages 2584-2592 ; 10735615 (ISSN) Vahdatkhah, P ; Sadrnezhaad, S. K ; Sharif University of Technology
    Springer Boston  2015
    Gold nanoparticles (AuNPs) of less than 50 nm diameter were electrodeposited from cyanide solution by pulsating electric current on modified copper and indium tin oxide (ITO) films coated on glass. Morphology, size, and composition of the deposited AuNPs were studied by X-ray photoelectron spectroscopy, atomic force microscopy, and field emission scanning electron microscopy. Effects of peak current density, pulse frequency, potassium iodide and cysteine on grain size, and morphology of the AuNPs were determined. Experiments showed that cathode current efficiency increases with the pulse frequency and the iodide ion. Size of the AuNPs increased with the current density. The number of...