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    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 Dastani, K ; 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... 

    Large scale inkjet-printing of carbon nanotubes electrodes for antioxidant assays in blood bags

    , Article Journal of Electroanalytical Chemistry ; Vol. 717-718 , 2014 , Pages 61-68 ; ISSN: 15726657 Lesch, A ; Cortes Salazar, F ; Prudent, M ; Delobel, J ; Rastgar, S ; Lion, N ; Tissot J. D ; Tacchini, P ; Girault, H. H ; Sharif University of Technology
    Herein, we present the large scale fabrication of carbon nanotubes (CNT) electrodes supported on flexible polymeric sheets by subsequent multilayer inkjet printing of a silver layer for electrical connection, CNT layers as active electrode material and an insulation layer to define a stand-alone CNT active electrode area with high accuracy. Optical and electrochemical characterization using several redox mediators demonstrates the reproducibility of the electrode surfaces and their functionality even with a single inkjet printed CNT layer. These electrodes are targeted to the clinical sector for the determination of the antioxidant power (AOP) of biologically relevant fluids by... 

    High-throughput, label-free isolation of white blood cells from whole blood using parallel spiral microchannels with u-shaped cross-section

    , Article Biosensors ; Volume 11, Issue 11 , 2021 ; 20796374 (ISSN) Mehran, A ; Rostami, P ; Saidi, M. S ; Firoozabadi, B ; Kashaninejad, N ; Sharif University of Technology
    MDPI  2021
    Rapid isolation of white blood cells (WBCs) from whole blood is an essential part of any WBC examination platform. However, most conventional cell separation techniques are labor-intensive and low throughput, require large volumes of samples, need extensive cell manipulation, and have low purity. To address these challenges, we report the design and fabrication of a passive, label-free microfluidic device with a unique U-shaped cross-section to separate WBCs from whole blood using hydrodynamic forces that exist in a microchannel with curvilinear geometry. It is shown that the spiral microchannel with a U-shaped cross-section concentrates larger blood cells (e.g., WBCs) in the inner... 

    Atorvastatin treatment softens human red blood cells: an optical tweezers study

    , Article Biomedical Optics Express ; Volume 9, Issue 3 , 2018 ; 21567085 (ISSN) Sheikh Hasani, V ; Babaei, M ; Azadbakht, A ; Pazoki Toroudi, H ; Mashaghi, A ; Moosavi Movahedi, A. A ; Seyed Reihani, .N ; Sharif University of Technology
    OSA - The Optical Society  2018
    Optical tweezers are proven indispensable single-cell micro-manipulation and mechanical phenotyping tools. In this study, we have used optical tweezers for measuring the viscoelastic properties of human red blood cells (RBCs). Comparison of the viscoelastic features of the healthy fresh and atorvastatin treated cells revealed that the drug softens the cells. Using a simple modeling approach, we proposed a molecular model that explains the drug-induced softening of the RBC membrane. Our results suggest that direct interactions between the drug and cytoskeletal components underlie the drug-induced softening of the cells. © 2018 Optical Society of America  

    Early detection of immunization: A study based on an animal model using 1H nuclear magnetic resonance spectroscopy

    , Article Pakistan Journal of Biological Sciences ; Volume 14, Issue 3 , 2011 , Pages 195-203 ; 10288880 (ISSN) Zamani, Z ; Arjmand, M ; Tafazzoli, M ; Ghohzadeh, A ; Pourfallah, F ; Sadeghi, S ; Mirzazadeh, R ; Mirkham, F ; Tahen, S ; Iravam, A ; Bayat, P ; Vahabi, F ; Sharif University of Technology
    Vaccines require a period of at least three months for clinical trials, hence a method that can identify elicitation of immune response a few days after the first dose is a necessity. Evolutionary variable selections are modeling approaches for proper manipulation of available data which were used to set up an animal model for classification of time dependent 'HNMR metabolomic profiles and pattern recognition of fluctuations of metabolites in two groups of male rabbits. One group of rabbits was immunized with human red blood cells and the other used as control. Blood was obtained every 48 h from each rabbit for a period of six weeks and the serum monitored for antibodies and metabolites by... 

    Design and simulation of a microfluidic device for acoustic cell separation

    , Article Ultrasonics ; Volume 84 , March , 2018 , Pages 234-243 ; 0041624X (ISSN) Shamloo, A ; Boodaghi, M ; Sharif University of Technology
    Elsevier B.V  2018
    Experimental acoustic cell separation methods have been widely used to perform separation for different types of blood cells. However, numerical simulation of acoustic cell separation has not gained enough attention and needs further investigation since by using numerical methods, it is possible to optimize different parameters involved in the design of an acoustic device and calculate particle trajectories in a simple and low cost manner before spending time and effort for fabricating these devices. In this study, we present a comprehensive finite element-based simulation of acoustic separation of platelets, red blood cells and white blood cells, using standing surface acoustic waves... 

    Numerical analysis of a dielectrophoresis field-flow fractionation device for the separation of multiple cell types

    , Article Journal of Separation Science ; Volume 40, Issue 20 , 2017 , Pages 4067-4075 ; 16159306 (ISSN) Shamloo, A ; Kamali, A ; Sharif University of Technology
    In this study, a dielectrophoresis field-flow fractionation device was analyzed using a numerical simulation method and the behaviors of a set of different cells were investigated. By reducing the alternating current frequency of the electrodes from the value used in the original setup configuration and increasing the number of exit channels, total discrimination in cell trajectories and subsequent separation of four cell types were achieved. Cells were differentiated based on their size and dielectric response that are represented in their real part of Clausius–Mossotti factor at different frequencies. A number of novel designs were also proposed based on the original setup configuration.... 

    Formulation and characterization of poly (ethylene glycol)-coated core-shell methionine magnetic nanoparticles as a carrier for naproxen delivery: growth inhibition of cancer cells

    , Article Cancers ; Volume 14, Issue 7 , 2022 ; 20726694 (ISSN) Yeganeh, F. E ; Yeganeh, A. E ; Yousefi, M ; Far, B. F ; Akbarzadeh, I ; Bokov, D. O ; Raahemifar, K ; Soltani, M ; Sharif University of Technology
    MDPI  2022
    An efficient and selective drug delivery vehicle for cancer cells can remarkably improve therapeutic approaches. In this study, we focused on the synthesis and characterization of magnetic Ni1−x Cox Fe2 O4 nanoparticles (NPs) coated with two layers of methionine and polyethylene glycol to increase the loading capacity and lower toxicity to serve as an efficient drug car-rier. Ni1−x Cox Fe2 O4 @Methionine@PEG NPs were synthesized by a reflux method then charac-terized by FTIR, XRD, FESEM, TEM, and VSM. Naproxen was used as a model drug and its loading and release in the vehicles were evaluated. The results for loading efficiency showed 1 mg of Ni1−x Cox Fe2 O4 @Methionine@PEG NPs could load... 

    Fluid particle diffusion through high-hematocrit blood flow within a capillary tube

    , Article Journal of Biomechanics ; Volume 44, Issue 1 , Jan , 2011 , Pages 170-175 ; 00219290 (ISSN) Saadatmand, M ; Ishikawa, T ; Matsuki, N ; Jafar Abdekhodaie, M ; Imai, Y ; Ueno, H ; Yamaguchi, T ; Sharif University of Technology
    Fluid particle diffusion through blood flow within a capillary tube is an important phenomenon to understand, especially for studies in mass transport in the microcirculation as well as in solving technical issues involved in mixing in biomedical microdevices. In this paper, the spreading of tracer particles through up to 20% hematocrit blood, flowing in a capillary tube, was studied using a confocal micro-PTV system. We tracked hundreds of particles in high-hematocrit blood and measured the radial dispersion coefficient. Results yielded significant enhancement of the particle diffusion, due to a micron-scale flow-field generated by red blood cell motions. By increasing the flow rate, the... 

    Association of glomerular and tubular dysfunction with glycaemic control, lipid, lipoprotein, apolipoprotein and antioxidant status in type 2 diabetes mellitus

    , Article Singapore Medical Journal ; Volume 48, Issue 9 , 2007 , Pages 840-846 ; 00375675 (ISSN) Farvid, M. S ; Djalali, M ; Siassi, F ; Farvid, S. S ; Sharif University of Technology
    Singapore Medical Association  2007
    Introduction: This study was conducted to investigate the relationship of glomerular and tubular dysfunctions with glycaemic control, lipid, lipoprotein, apolipoproteins and antioxidant status in 72 patients with type 2 diabetes mellitus. Methods: Urine albumin concentration was measured by immunoturbidimetric and urine N-acetyl-beta-D-glucosaminidase (NAG) and alanine aminopeptidase (AAP) activities with colorimetric methods. Glycated haemoglobin was measured using affinity chromatography. Erythrocyte glu ta thione reductase and glutathione peroxidase activities and serum levels of malondialdehyde, lipids, lipoproteins and apolipoproteins were determined in patients with type 2 diabetes...