Search for: electrophoresis
Total 84 records
Nanodiamonds for surface engineering of orthopedic implants: Enhanced biocompatibility in human osteosarcoma cell culture [electronic resource], Article Diamond and Related Materials ; Volume 40, 2013, Pages 107-114 ; Shokrgozar, M. A ; Mehrjoo, M ; Tamjid, E ; Simchi, A ; Sharif University of Technology
Recently, nanodiamonds have attracted interest in biomedical applications such as drug delivery, targeted cancer therapies, fabrication of tissue scaffolds, and biosensors. We incorporated diamond nanoparticles in alginate–bioactive glass films by electrophoretic process to prepare functional coatings for biomedical implants. Turbidity examination by time-resolved laser transmittance measurement revealed that a stable multi-component aqueous suspension of alginate, bioactive glass and diamond particles could be obtained at concentrations of 0.6, 1.3, and 0.65 g/l, respectively. Uniform films with ~ 5 μm thickness were deposited on 316 stainless steel foils by employing constant field...
Article Journal of King Saud University - Science ; Volume 33, Issue 7 , 2021 ; 10183647 (ISSN) ; Nadeem, A ; Maalik, S ; Mushtaq, S ; Iqbal, N ; Khan, A. K ; Shabbir, A ; Imran, M ; Niaz, S ; Yasin, M ; Qayyum, M. A ; Ahmad, B ; Skalicky, M ; Alharbi, S. A ; Alfarraj, S ; Sharif University of Technology
Elsevier B.V 2021
Single cell gel electrophoresis was used to observe the effect of bifenthrin and chlorpyrifos on Labeo rohita. The present work was planned to study the genotoxic effect of pesticide mixture on the major indian carp, L. rohita at sub-lethal concentration 33% LC50. First of all, 96-hr LC50 was determined for L. rohita, then fish was given sub-lethal environment for 70 days. Erythrocytes from blood were taken after each fortnight for the assessment of time dependent DNA damage (% damage), aggregate tail length of comets and genomic destruction. There was increase in damage up to 56 days and after that a slight decrease was observed in next fourteen days. After statistical analysis, it was...
Article 5th International Conference on Perspective Technologies and Methods in MEMS Design, MEMSTECH 2009, Lviv-Polyana, 22 April 2009 through 24 April 2009 ; 2009 , Pages 136-140 ; 9789662191066 (ISBN) ; Afsharikia, S ; Taghizadeh Manzari, M.T ; Sharif University of Technology
Chip-based micro fluidic separation systems often use serpentine channels to attain long separation lengths in a compact area. Such designs suffer from the dispersion, mostly 'racetrack' effect, due to the bends in the micro channels. The main goal of this paper is obtaining a model which has minimal racetrack in a serpentine geometry. A numerical analysis leads us to an optimized model which is different from previous attempts in this field. Our model uses modified turn radii, optimal length between bends with a constant zeta-potential boundary condition and a constant width through micro channel turns. It is shown that traveling fluid in this geometry has minimal dispersion as well as...
Article Journal of AOAC International ; Vol. 97, issue. 1 , 2014 , p. 12-18 ; Leardi, R ; Jalali-Heravi, M ; Sharif University of Technology
This paper reviews the applications of experimental design to optimize some analytical chemistry techniques such as extraction, chromatography separation, capillary electrophoresis, spectroscopy, and electroanalytical methods
Article Electrophoresis ; Volume 28, Issue 3 , 2007 , Pages 301-308 ; 01730835 (ISSN) ; Sarbolouki, M. N ; Rouhani, S ; Sharif University of Technology
The dependence of the mobility of DNA molecules through an hexagonal array of micropillars on their length and the applied electric field was investigated and it was found that mobility is a nonmonotonic function of their length. Results also revealed that the size dependence of the DNA mobility depends on the applied electric field and there is a crossover around E ≈ 25 V/cm for the mobility of λ-DNA and T4-DNA. These observations are explained in terms of the diffusion process inside the structure affected by the solvent and are modeled using the Langevin and its corresponding Fokker-Planck equations. The phenomenon is generalized under three regimes in a phase diagram relating the...
Voltammetric determination of thiocytosine based on its electrocatalytic oxidation on the surface of carbon-paste electrode modified with cobalt schiff base complexes, Article Journal of Solid State Electrochemistry ; Volume 11, Issue 8 , 2007 , Pages 1133-1138 ; 14328488 (ISSN) ; Amiri, M ; Sharif University of Technology
The electrochemical oxidation of thiocytosine on the surface of carbon-paste electrode modified with Schiff base (salophen derivatives) complexes of cobalt is studied. The effect of the substituents in the structure of salophen on the catalytic property of the modified electrode is investigated by using cyclic and differential pulse voltammetry. Cobalt (II)-5-nitrosalophen, because of its electrophilic functional groups, leads to a considerable enhancement in the catalytic activity, sensitivity (peak current), and a marked increase in the anodic potential of the modified electrode. The differential pulse voltammetry is applied as a very sensitive method for the detection of thiocytosine. The...
Artificial neural network modeling of peptide mobility and peptide mapping in capillary zone electrophoresis, Article Journal of Chromatography A ; Volume 1096, Issue 1-2 , 2005 , Pages 58-68 ; 00219673 (ISSN) ; Shen, Y ; Hassanisadi, M ; Khaledi, M. G ; Sharif University of Technology
Recently, we have developed an artificial neural network model, which was able to predict accurately the electrophoretic mobilities of relatively small peptides. To examine the robustness of this methodology, a 3-3-1 back-propagation artificial neural network (BP-ANN) model was developed using the same inputs as the previous model, which were the Offord's charge over mass term (Q/M2/3), corrected steric substituent constant (E s,c) and molar refractivity (MR). The data set consisted of 102 peptides with a larger range of size than that of our earlier report - up to 42 amino acid residues as compared to 13 amino acids in the initial study - that also included highly charged and hydrophobic...
Continuous size-based focusing and bifurcating microparticle streams using a negative dielectrophoretic system, Article Microfluidics and Nanofluidics ; Volume 14, Issue 1-2 , 2013 , Pages 265-276 ; 16134982 (ISSN) ; Saidi, M. S ; Sadeghi, A ; Sani, M
Dielectrophoresis (DEP) is an electrokinetic phenomenon which is used for manipulating micro- and nanoparticles in micron-sized devices with high sensitivity. In recent years, electrode-based DEP by patterning narrow oblique electrodes in microchannels has been used for particle manipulation. In this theoretic study, a microchannel with triangular electrodes is presented and a detailed comparison with oblique electrodes is made. For each shape, the behavior of particles is compared for three different configurations of applied voltages. Electric field, resultant DEP force, and particle trajectories for configurations are computed by means of Rayan native code. The separation efficiency of...
Self-cleaning TiO2 nanofilms on FTO glass: Influence of electrophoretic deposition and UV irradiation conditions, Article Journal of Nano Research ; Volume 30 , 2015 , Pages 39-49 ; 16625250 (ISSN) ; Ghorbani, M ; Dolati, A ; Sharif University of Technology
Trans Tech Publications Ltd 2015
In this research, anatase TiO2 nano-particles were electrophoretically deposited on the FTO glass. This investigation was focused on the self-cleaning property of TiO2 coatings and the effects of different parameters on this characteristic such as: applied voltages during electrophoretic depositions and durations of UV irradiation. Electrophoretic depositions of suspensions were performed in different voltages of 10, 30 and 60 V (for 10 s) at room temperature. TiO2 coatings were sintered in 450oC for 1 hr. The phase transformation of TiO2 films was considered using XRD. Morphology, average particle size and the thickness of TiO2 films was analyzed using FESEM microscope. The photocatalytic...
Article 2016 23rd Iranian Conference on Biomedical Engineering and 2016 1st International Iranian Conference on Biomedical Engineering, ICBME 2016, 23 November 2016 through 25 November 2016 ; 2017 , Pages 93-96 ; 9781509034529 (ISBN) ; Mohammadi, A ; Kalhor, H ; Sharif University of Technology
in recent decades, DEP due to its high efficiency has been exploited widely in separation and manipulation of bioparticles. In the present work a simple, low-cost, and efficient procedure for fabrication of microfluidic chips applied in medicine and biochemistry has been presented. In this method, electrodes are not in direct contact with biological samples which results in elimination of conventional systems' cons. Efficacy of the designed system has been evaluated by injecting samples containing yeast and Ecoli cells into the system and analyzing their trajectory. Experimental results demonstrate that precise adjustment of voltage and frequency can lead to the desired separation in this...
Article Biomedical Optics Express ; Volume 10, Issue 11 , 2019 , Pages 5639-5649 ; 21567085 (ISSN) ; Azadbakht, A ; Mollaei, P ; S. Reihani, N. S ; Sharif University of Technology
OSA - The Optical Society 2019
The force experienced by a neutral dielectric object in the presence of a spatially non-uniform electric field is referred to as dielectrophoresis (DEP). The proper quantification of DEP force in the single-cell level could be of great importance for the design of high-efficiency micro-fluidic systems for the separation of biological cells. In this report we show how optical tweezers can be properly utilized for proper quantification of DEP force experienced by a human RBC. By tuning the temporal frequency of the applied electric field and also performing control experiments and comparing our experimental results with that of theoretically calculated, we show that the measured force is a...
Article Biomedical Physics and Engineering Express ; Volume 5, Issue 3 , 2019 ; 20571976 (ISSN) ; Sasanpour, P ; Fardindoost, S ; Irajizad, A ; Sharif University of Technology
Institute of Physics Publishing 2019
A novel approach for particles size separation based on dielectrophoresis (DEP) method is introduced and analyzed both computationally and experimentally. The proposed technique has been utilized for the separation of polystyrene (PS) particles with 8, 6 and 2 μm diameters passing through microchannels with planar electrodes. The performance of the technique has been computationally analyzed using the finite element method (FEM). Considering the structure of the planar electrodes, we propose an approach based on applying an electric potential between one of the global electrodes, and a needle touched the top of the cell suspension. Results of both simulation and experiment show that by...
Effect of input voltage frequency on the distribution of electrical stresses on the cell surface based on single-cell dielectrophoresis analysis, Article Scientific Reports ; Volume 10, Issue 1 , 2020 ; Moghimi Zand, M ; Kavand, H ; Javidi, R ; Hadi, A ; Valadkhani, Z ; Renaud, P ; Sharif University of Technology
Nature Research 2020
Electroporation is defined as cell membrane permeabilization under the application of electric fields. The mechanism of hydrophilic pore formation is not yet well understood. When cells are exposed to electric fields, electrical stresses act on their surfaces. These electrical stresses play a crucial role in cell membrane structural changes, which lead to cell permeabilization. These electrical stresses depend on the dielectric properties of the cell, buffer solution, and the applied electric field characteristics. In the current study, the effect of electric field frequency on the electrical stresses distribution on the cell surface and cell deformation is numerically and experimentally...
Article Nanoscale ; Volume 7, Issue 11 , Feb , 2015 , Pages 5004-5013 ; 20403364 (ISSN) ; Dinarvand, R ; Ghahremani, M. H ; Hormozi-Nezhad, M. R ; Mahmoudi, Z ; Hajipour, M. J ; Atyabi, F ; Ghavami, M ; Mahmoudi, M ; Sharif University of Technology
Royal Society of Chemistry 2015
Protein fibrillation process (e.g., from amyloid beta (Aβ) and α-synuclein) is the main cause of several catastrophic neurodegenerative diseases such as Alzheimer's and Parkinson diseases. During the past few decades, nanoparticles (NPs) were recognized as one of the most promising tools for inhibiting the progress of the disease by controlling the fibrillation kinetic process; for instance, gold NPs have a strong capability to inhibit Aβ fibrillations. It is now well understood that a layer of biomolecules would cover the surface of NPs (so called "protein corona") upon the interaction of NPs with protein sources. Due to the fact that the biological species (e.g., cells and amyloidal...
Expression of functional recombinant human tissue transglutaminase (TG2) using the bac-to-bac baculovirus expression system, Article Advanced Pharmaceutical Bulletin ; Volume 6, Issue 1 , 2016 , Pages 49-56 ; 22285881 (ISSN) ; Azari, S ; Kalhor, H. R ; Sharif University of Technology
Tabriz University of Medical Sciences
Tissue transglutaminase (TG2) is a unique multifunctional enzyme. The enzyme possesses enzymatic activities such as transamidation/crosslinking and non-enzymatic functions such as cell migration and signal transduction. TG2 has been shown to be involved in molecular mechanisms of cancers and several neurodegenerative diseases such as Alzheimer's disease. The present study aimed at cloning and expression of full length human TG2 in Bac-to-Bac baculovirus expression system and evaluation of its activity. Methods: pFastBac HTA donor vector containing coding sequence of human TG2 was constructed. The construct was transformed to DH10Bac for generating recombinant bacmid. The verified bacmid was...
Article Journal of Physical Chemistry C ; Volume 112, Issue 47 , 2008 , Pages 18686-18689 ; 19327447 (ISSN) ; Taghavinia, N ; Sharifi, N ; Chavoshi, M ; Rahman, M ; Sharif University of Technology
TiO2 deposited on a membrane of Ag fibers was prepared as a photoelectrochemical cell electrode. Ag fibers were made by reduction of Ag complexes on cellulose fibers, followed by burning out the template. TiO 2 photocatalyst layers were grown on the fibers by electrophoretic deposition of TiO2 nanoparticles. Ag fibers could be uniformly deposited. Photocatalytic tests by dye decomposition and electrochemical impedance spectroscopy (EIS) under UV illumination demonstrate that Ag fibers act as a good substrate that provides both high surface area and good separation of photogenerated electron-hole pairs and causes the enhancement of photocatalytic activity in comparison with a thin film of...
Graphene oxide sheets involved in vertically aligned zinc oxide nanowires for visible light photoinactivation of bacteria, Article Journal of Alloys and Compounds ; Vol. 612 , 2014 , pp. 380-385 ; ISSN: 09258388 ; Rahighi, R ; Akhavan, O ; Moshfegh, A ; Sharif University of Technology
Vertically aligned ZnO nanowires (NWs) hybridized with reduced graphene oxide sheets (rGO) were applied in efficient visible light photoinactivation of bacteria. To incorporate graphene oxide (GO) sheets within the NWs two different methods of drop-casting and electrophoretic deposition (EPD) were utilized. The EPD method yielded effective penetration of the positively charged GO sheets into the NWs to form a spider net-like structure, whereas the drop-casting method resulted in only a surface coverage of the GO sheets on top of the NWs. The electrical connection between the EPD-incorporated sheets and the NWs was checked by monitoring the electron transfer from UV-assisted photoexcited ZnO...
Development of electrophoretically deposited hydroxyapatite coatings on anodized nanotubular TiO2 structures: Corrosion and sintering temperature, Article Applied Surface Science ; Vol. 301 , May , 2014 , pp. 250-257 ; ISSN: 01694332 ; Batmanghelich, F ; Afshar, A ; Dolati, A ; Mortazavi, G ; Sharif University of Technology
Hydroxyapatite (HA) coatings in and onto anodized TiO2 nanotube arrays were presented and prepared by electrophoretic deposition technique (EPD). Coatings were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). EPD proved to be an innovative and versatile technique to coat HA on and into nanotubular structures of TiO2 with enhanced adhesion between nanotubes and HA particles provided by mechanical interlocking. After EPD of HA on TiO2 layer, samples were sintered at 400 °C, 600 °C and 800 °C for 2 h in an Ar atmosphere. Effect of EPD processing parameters on thickness of the deposits and rate of deposition was elucidated for HA coatings on the nanotubular TiO2...
Article Journal of the European Ceramic Society ; Volume 33, Issue 10 , 2013 , Pages 1815-1823 ; 09552219 (ISSN) ; Yar, A. Y ; Vafaeenezhad, S ; Sani, M. A. F ; Simchi, A ; Sharif University of Technology
Functionally-graded NiO-8. mol % YSZ composite films were prepared by a controlled voltage-decay electophoretic deposition (EPD) process. The films consisted of three layers with varying NiO concentrations and porosities. Effects of different parameters including the type of the organic media, solid concentration, NiO:YSZ ratio, and iodine on the stability of EPD suspensions and deposition kinetics were studied. A stable NiO-YSZ suspension was attained in isopropanol with NiO-YSZ ratio of 60:40 and iodine concentration of 0.5. mM. The composite film contained varying NiO concentration from 46. wt.% near the substrate to 32. wt.% close to the electrolyte with 42. wt% NiO in the intermediate...
Article Materials Letters ; Volume 65, Issue 23-24 , 2011 , Pages 3421-3423 ; 0167577X (ISSN) ; Moshayedi, Sh ; Ghaffari, S. A ; Rezaei, H. R ; Golestani Fard, F ; Sharif University of Technology
Zirconia/Hydroxyapatite composites containing 20-50 wt.% 8YSZ were prepared on Ti/TiO2 substrates by electrophoretic deposition (EPD)/micro-arc oxidation (MAO) process. Titania, as an inner layer, was grown on the Ti plates using MAO treatment in order to form a strong join between substrate and HAp. These composites were produced by EPD in ethanol containing ZrO2/HAp particles at 50, 100 and 150 V in 1 min. Asprepared samples were sintered at 900, 1100 and 1300 °C. HAp, β-TCP, CaZrO3 phases were identified using X-ray diffractometry analysis (XRD). Scanning electron microscopy (SEM) utilized to study the surface morphology indicated a crack free microstructure at 1300 °C