Search for: complex-formation
Synthesis and X-ray structural characterization of unsymmetrical tetradentate complexes of Ni(II) and Cu(II), Article Synthesis and Reactivity in Inorganic and Metal-Organic Chemistry ; Volume 32, Issue 2 , 2002 , Pages 345-355 ; 00945714 (ISSN) ; Boghaei, D. M ; Sharif University of Technology
The unsymmetrical tetradentate Schiff base H2L was prepared by the reaction of salicylaldehyde with the mono Schiff base derived from o-phenylenediamine and o-hydroxyacetophenone (HL1). NiL and CuL complexes were prepared and characterized by 1H NMR, IR and single crystal X-ray structure determination. Crystal data for NiL: triclinic space group P-1, a = 7.190 (2) Å, b = 13.059 (4) Å, c = 17.867 (10) Å, α = 74.888 (10)°, β = 84.206 (10)°, γ = 86.542 (2)° and z = 4. Crystal data for CuL: monoclinic space group P2I/n, a = 12.8209 (6) Å, b = 6.988 (3) Å, c = 18.601 (9) Å, β = 105.15° and z = 4. The Ni and Cu atoms have a slightly distorted square-planar coordination geometry
Highly dispersible and magnetically recyclable poly(1-vinyl imidazole) brush coated magnetic nanoparticles: An effective support for the immobilization of palladium nanoparticles, Article New Journal of Chemistry ; Volume 40, Issue 2 , 2016 , Pages 1729-1736 ; 11440546 (ISSN) ; Safaie, N ; Hosseini, S. H ; Bennett, C ; Sharif University of Technology
Royal Society of Chemistry
A heterogeneous recoverable catalyst was prepared via the complexation of palladium onto the surface of magnetic nanoparticles coated by a poly(1-vinyl imidazole) brush. The stable, active and reusable catalyst was proven to be highly active in aerobic oxidation of primary and secondary alcohols with excellent yields. Only 0.1 mol% of the catalyst was used to oxidize 1 mmol of primary and secondary alcohols. The catalyst was readily recovered and reused up to 10 times under the described reaction conditions without significant loss of activity
Article Advanced International Conference on Telecommunications andInternational Conference on Internet and Web Applications and Services, AICT/ICIW'06, Guadelope, 19 February 2006 through 25 February 2006 ; Volume 2006 , 2006 , Pages 42- ; 0769525229 (ISBN); 9780769525228 (ISBN) ; Ghaemmaghami, S ; Khazaei, S ; Sharif University of Technology
Format compliance, a desirable feature of multimedia security systems, means that the secured bitstream resembles the unprotected compressed bitstream. It is called full format compliance, if the scrambled stream can be decoded by a typical decoder. In this paper, we address the issues that are to be carefully taken into account to develop efficient fully format compliant scrambling methods for compressed video. We also propose new selective scrambling methods for securing compressed video streams. The security issues, in different parts of these scrambling methods, are analyzed and their impact on bit-rate and complexity is discussed. We show that our scrambling methods provide...
Factors affecting platinum extraction from used reforming catalysts in iodine solutions at temperatures up to 95 °C, Article Hydrometallurgy ; Volume 97, Issue 1-2 , 2009 , Pages 119-125 ; 0304386X (ISSN) ; Baghalha, M ; Sharif University of Technology
Platinum extraction from the spent reforming catalysts in iodine-iodide solutions at temperatures from 25 to 95 °C was investigated. The reforming catalyst mostly consists of a porous gamma alumina support with metallic platinum finely dispersed on the walls of the nano-pores of the catalyst support. The effect of a variety of factors, including catalyst particle size, impeller agitation speed, reactant concentrations, liquid to solid mass ratio, temperature and the solution pH on the Pt extraction rate and recovery were investigated. It was found that the catalyst particle sizes less than 106 μm and impeller agitation speed higher than 700 rpm eliminated the effects of catalyst size and...
Efficient aerobic oxidation of alcohols using a novel combination N-hydroxy phthalimide (NHPI) and a recyclable heterogeneous cobalt complex, Article Journal of Molecular Catalysis A: Chemical ; Volume 232, Issue 1-2 , 2005 , Pages 95-99 ; 13811169 (ISSN) ; Karimi, B ; Sharif University of Technology
A novel combination between N-hydroxy phthalimide (NHPI) and a silica based cobalt (II) interphase catalyst (1) efficiently catalyzes the aerobic oxidation of various types of alcohols to the corresponding carbonyl compounds. The catalyst 1 shows high thermal stability and also could be recovered and reused in combination with NHPI for at least five reaction cycles without considerable loss of reactivity. © 2005 Elsevier B.V. All rights reserved
Article Colloids and Surfaces A: Physicochemical and Engineering Aspects ; Vol. 460 , October , 2014 , pp. 361-368 ; ISSN: 09277757 ; Krzan, M ; Lotfi, M ; Dukhin, S. S ; Kovalchuk, V. I ; Javadi, A ; Gunes, D. Z ; Gehin-Delval, C ; Malysa, K ; Miller, R ; Sharif University of Technology
The rising velocity of air bubbles in surfactant solutions is a sensitive measure for the formation of a dynamic adsorption layer (DAL) at the bubble surface. Due to a certain surface coverage by adsorbed species the bubble surface starts to become immobilized and the rising velocity is retarded. There is a large difference in the retardation effect in presence of the protein β-lactoglobulin (BLG) alone and its mixed solutions with surfactants. In presence of added surfactants BLG forms complexes, which adsorb and retard the bubble rising velocity according to their respective surface activity and adsorption kinetics. While the nonionic surfactant C12DMPO does not show significant increase...
Amino acids and their complex formation properties with divalent metal ions, a comparative investigation of structure and stability in binary systems, Article Current Pharmaceutical Analysis ; Volume 10, Issue 2 , 2014 , Pages 122-134 ; ISSN: 15734129 ; Sharif University of Technology
A comparative investigation has been developed for the stability constants of several amino acid complexes with divalent metal ions, which have been determined by potentiometric pH titration. Depending on the metal ion-binding properties, vital differences in the building complexes were observed. The present study indicates that in some M(L) complexes, metal ions are arranged in carboxyl groups, but in other M(L)complexes, some metal ions are able to build chelate over amine groups. The results mentioned-above demonstrate that for some M(L) complexes, the stability constants are also largely determined by the affinity of metal ions for amine group. This leads to a kind of selectivity of...
Binding assessment of two arachidonic-based synthetic derivatives of adrenalin with β-lactoglobulin: Molecular modeling and chemometrics approach, Article Biophysical Chemistry ; Volume 207 , 2015 , Pages 97-106 ; 03014622 (ISSN) ; Bordbar, A. K ; Akvan, N ; Parastar, H ; Fani, N ; Gretskaya, N. M ; Bezuglov, V. V ; Haertlé, T ; Sharif University of Technology
A computational approach to predict the main binding modes of two adrenalin derivatives, arachidonoyl adrenalin (AA-AD) and arachidonoyl noradrenalin (AA-NOR) with the β-lactoglubuline (BLG) as a nano-milk protein carrier is presented and assessed by comparison to the UV-Vis absorption spectroscopic data using chemometric analysis. Analysis of the spectral data matrices by using the multivariate curve resolution-alternating least squares (MCR-ALS) algorithm led to the pure concentration calculation and spectral profiles resolution of the chemical constituents and the apparent equilibrium constants computation. The negative values of entropy and enthalpy changes for both compound indicated...
Structural and optical properties of Fe and Zn substituted CuInS
Journal of Materials Chemistry C
Volume 3, Issue 4
; Tahir, M. N
; Zad, A. I
; Mirkazemi, S. M
; Ghazemzadeh, R
; Tremel, W
Sharif University of Technology
2 nanoparticles synthesized by a one-pot facile method
Royal Society of Chemistry 2015
We substitute indium present in the CuInS
2 ternary compound by iron and zinc using a facile one-pot synthesis method. The quaternary compound of CuIn 1-xM xS 2 (M = Fe and Zn) was synthesized by dissolving CuCl, InCl 3, FeCl 3, Zn(ac) 2 and SC(NH 2) 2 as precursors in 1-octadecene, oleylamine and oleic acid as non-coordinating, coordinating and capping agent solvents, respectively. Oleic acid, oleylamine and thiourea were used respectively as a hard Lewis base, borderline Lewis base (in comparison with oleic acid) and soft Lewis base to form appropriate complexes. The complex formation, structure, and...
Theoretical aspects of the enhancement of metal binding affinity by intramolecular hydrogen bonding and modulating p: K a values, Article New Journal of Chemistry ; Volume 41, Issue 24 , 2017 , Pages 15110-15119 ; 11440546 (ISSN) ; Fattahi, A ; Sharif University of Technology
Royal Society of Chemistry 2017
Polyols were used as model ligands for Mg2+, Ca2+, and Zn2+ complexes to study the role of the hydrogen bond network on the metal binding affinity and modulation of successive pKa values using density functional theory. The results confirm that the acidity of polyols dramatically increases upon metal complexation in the order Zn2+ > Mg2+ > Ca2+. For example, the three H-site positions in the hydroxyl groups of the heptaol, bound to Zn2+, are 11.2, 29.9, and 30.9 pKa units (in methanol) more acidic than those of pure heptaol. This acidity enhancement leads to making polyols as good ligands toward complexation. For instance, the formation constants of the heptaol in the presence of Zn2+, Mg2+,...
Spectroscopic and thermodynamic studies of interaction between dopamine and cobalt (III) schiff-base complexes, Article Scientia Iranica ; Volume 16, Issue 2 C , 2009 , Pages 89-93 ; 10263098 (ISSN) ; Boghaei, D. M ; Sharif University of Technology
In this paper, the interactions of cobalt(III) tetradentate Schiff-base complexes, [Co(S-MeO-salophen)]ClO4, (1), [Co(5-NO 2-salophen)]ClO4, (2), and [Co(5-Br-salophen)]ClO 4, (3), with dopamine, an important neurotransmitter, have been investigated. The formation and kinetic constants for complex formation of [Co(3-MeO-salophen)]ClO4, (1), with dopamine were determined spectrophotometrically in H2O/EtOH solution (4:1) at 30°C by using the Benesi-Hildbrand and Guggenheim equations, respectively. The stoichiometry has been found to be 1:1. The rate and equilibrium constants for the coordination of dopamine to (Co(3-MeO-salophen)]ClO4 were found to be 0.0053 min-1 and 1600 dm3 mol-1,...
Electrodeposition of Ni-WndashB nanocomposite from tartrate electrolyte as alternative to chromium plating, Article Surface Engineering ; Volume 25, Issue 5 , 2009 , Pages 382-388 ; 02670844 (ISSN) ; Abdolmaleki, M ; Seyed Sadjadi, S. A ; Raghibi Boroujeni, M ; Arshadi, M. R ; Khoshvaght, H ; Sharif University of Technology
The effect of the bath chemistry and operating conditions on the chemical composition, microstructure and properties of NiWmdashB alloys deposited from tartrate baths on working electrode was studied for the first time by the pulsed current method. The investigations included the measurement of the current efficiencies and determination of the tungsten content in the electrodeposits. UV spectrometry was used for characterisation of complex formation. The grain size of deposits was determined by XRD. Also, the morphology of the deposits was studied by SEM. Amorphous NimdashWB alloys were successfully obtained by electrodeposition from the tartrate bath. The corrosion behaviour of NiWmdashB...
An improved synthesis and preliminary biodistribution study of a technetium-99m-labeled2-amino-2-deoxy(thioacetyl)-D-glucose complex ([ 99mTc]-TA-DG) as a tumor imaging agent, Article Iranian Journal of Nuclear Medicine ; Volume 15, Issue 28 , 2007 , Pages 43-48 ; 16812824 (ISSN) ; Sadeghzadeh, M ; Charkhlooie, G ; Haghir Ebrahimabadi, K ; Saeedi, M. R ; Sharif University of Technology
Introduction: This report describes the synthesis of 2-Amino-2-deoxy(S- benzoylthioacetyl)-D-glucose (S-Bz-TA-DG), radiolabeled with [ 99mTc(CO)3(OH2)3]+ complex with a procedure including deprotection of the benzoyl group, characterization by HPLC using a C18 reverse phase column and preliminary biodistribution study in normal mice. Methods: [99mTc(CO) 3(H2O)3]+ complex was used to label TA-DG with 99mTc. This complex was prepared using up to 46 mCi of Na99mTcO4 in 1mL saline. The radiochemical purity (>95%) was determined by TLC in normal saline solution as the mobile phase. Radio-HPLC analysis of [99mTc]-(TA-DG) at pH=9.5-10, revealed that labeling with 99mTc resulted in the formation of...
Homozygous mutations in C14orf39/SIX6OS1 cause non-obstructive azoospermia and premature ovarian insufficiency in humans, Article American Journal of Human Genetics ; Volume 108, Issue 2 , 2021 , Pages 324-336 ; 00029297 (ISSN) ; Jiao, Y ; Khan, R ; Jiang, X ; Javed, A. R ; Ali, A ; Zhang, H ; Zhou, J ; Naeem, M ; Murtaza, G ; Li, Y ; Yang, G ; Zaman, Q ; Zubair, M ; Guan, H ; Zhang, X ; Ma, H ; Jiang, H ; Ali, H ; Dil, S ; Shah, W ; Ahmad, N ; Zhang, Y ; Shi, Q ; Sharif University of Technology
Cell Press 2021
Human infertility is a multifactorial disease that affects 8%–12% of reproductive-aged couples worldwide. However, the genetic causes of human infertility are still poorly understood. Synaptonemal complex (SC) is a conserved tripartite structure that holds homologous chromosomes together and plays an indispensable role in the meiotic progression. Here, we identified three homozygous mutations in the SC coding gene C14orf39/SIX6OS1 in infertile individuals from different ethnic populations by whole-exome sequencing (WES). These mutations include a frameshift mutation (c.204_205del [p.His68Glnfs∗2]) from a consanguineous Pakistani family with two males suffering from non-obstructive...
Design of experiment, preparation, and in vitro biological assessment of human amniotic membrane extract loaded nanoparticles, Article Current Pharmaceutical Biotechnology ; Volume 21, Issue 3 , 2020 , Pages 256-267 ; Atyabi, F ; Khoshayand, M. R ; Mahbod, R ; Cohan, R. A ; Akbarzadeh, I ; Bakhshandeh, H ; Sharif University of Technology
Bentham Science Publishers 2020
Background: Human amniotic membrane grafting could be potentially useful in ocular surface complications due to tissue similarity and the presence of factors that reduce inflammation, vascu-larization, and scarring. However, considerations like donor-derived infectious risk and the requirement of an invasive surgery limit the clinical application of such treatments. Moreover, the quick depletion of bioactive factors after grafting reduces the efficacy of treatments. Therefore, in the current study, the possibility of nano delivery of the bioactive factors extracted from the human amniotic membrane to the ocular surface was investigated. Materials and Methods: Nanoparticles were prepared...
Article Biomaterials Science ; Volume 8, Issue 4 , 2020 , Pages 1127-1136 ; Mostafavi, E ; Shokrgozar, M. A ; Tamjid, E ; Webster, T. J ; Annabi, N ; Simchi, A ; Sharif University of Technology
Royal Society of Chemistry 2020
The delivery of growth factors is often challenging due to their short half-life, low stability, and rapid deactivation. In native tissues, the sulfated residual of glycosaminoglycan (GAG) polymer chains of proteoglycans immobilizes growth factors through the proteoglycans'/proteins' complexation with nanoscale organization. These biological assemblies can influence growth factor-cell surface receptor interactions, cell differentiation, cell-cell signaling, and mechanical properties of the tissues. Here, we introduce a facile procedure to prepare novel biomimetic proteoglycan nanocarriers, based on naturally derived polymers, for the immobilization and controlled release of growth factors....
Challenges and future prospects for the delivery of biologics: oral mucosal, pulmonary, and transdermal routes, Article AAPS Journal ; Volume 19, Issue 3 , 2017 , Pages 652-668 ; 15507416 (ISSN) ; Fathe, K. R ; Brunaugh, A ; Ferrati, S ; Li, S ; Montenegro Nicolini, M ; Mousavikhamene, Z ; McConville, J. T ; Prausnitz, M. R ; Smyth, H. D. C ; Sharif University of Technology
Springer New York LLC 2017
Biologic products are large molecules such as proteins, peptides, nucleic acids, etc., which have already produced many new drugs for clinical use in the last decades. Due to the inherent challenges faced by biologics after oral administration (e.g., acidic stomach pH, digestive enzymes, and limited permeation through the gastrointestinal tract), several alternative routes of administration have been investigated to enable sufficient drug absorption into systemic circulation. This review describes the buccal, sublingual, pulmonary, and transdermal routes of administration for biologics with relevant details of the respective barriers. While all these routes avoid transit through the...