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    Brain-on-a-chip: Recent advances in design and techniques for microfluidic models of the brain in health and disease

    , Article Biomaterials ; Volume 285 , 2022 ; 01429612 (ISSN) Amirifar, L ; Shamloo, A ; Nasiri, R ; de Barros, N. R ; Wang, Z. Z ; Unluturk, B. D ; Libanori, A ; Ievglevskyi, O ; Diltemiz, S. E ; Sances, S ; Balasingham, I ; Seidlits, S. K ; Ashammakhi, N ; Sharif University of Technology
    Elsevier Ltd  2022
    Abstract
    Recent advances in biomaterials, microfabrication, microfluidics, and cell biology have led to the development of organ-on-a-chip devices that can reproduce key functions of various organs. Such platforms promise to provide novel insights into various physiological events, including mechanisms of disease, and evaluate the effects of external interventions, such as drug administration. The neuroscience field is expected to benefit greatly from these innovative tools. Conventional ex vivo studies of the nervous system have been limited by the inability of cell culture to adequately mimic in vivo physiology. While animal models can be used, their relevance to human physiology is uncertain and... 

    Simultaneous leaching of Cu, Al, and Ni from computer printed circuit boards using Penicillium simplicissimum

    , Article Resources, Conservation and Recycling ; Volume 177 , 2022 ; 09213449 (ISSN) Esmaeili, A ; Arshadi, M ; Yaghmaei, P.O. C. A. P. E. D. S ; Sharif University of Technology
    Elsevier B.V  2022
    Abstract
    A short lifespan and increased consumption patterns make e-waste the world's fastest-growing waste stream. Computers are one of the most significant parts of e-waste. Recycling of e-waste has been introduced as the main solution to deal with environmental problems and to save natural mines. This research aims to investigate the bioleaching of Cu, Ni, and Al from computer printed circuit boards (CPCBs) using Penicillium simplicissimum. The adaptation phase began at 1 g/l CPCBs powder with 107 spores and final pulp density was reached at 30 g/l. The most effective parameters including pulp density, initial pH, and the sucrose concentration were optimized to achieve maximum simultaneous... 

    Nanotechnology-assisted microfluidic systems: From bench to bedside

    , Article Nanomedicine ; Volume 16, Issue 3 , 2021 , Pages 237-258 ; 17435889 (ISSN) Rabiee, N ; Ahmadi, S ; Fatahi, Y ; Rabiee, M ; Bagherzadeh, M ; Dinarvand, R ; Bagheri, B ; Zarrintaj, P ; Saeb, M. R ; Webster, T. J ; Sharif University of Technology
    Future Medicine Ltd  2021
    Abstract
    With significant advancements in research technologies, and an increasing global population, microfluidic and nanofluidic systems (such as point-of-care, lab-on-a-chip, organ-on-a-chip, etc) have started to revolutionize medicine. Devices that combine micron and nanotechnologies have increased sensitivity, precision and versatility for numerous medical applications. However, while there has been extensive research on microfluidic and nanofluidic systems, very few have experienced wide-spread commercialization which is puzzling and deserves our collective attention. For the above reasons, in this article, we review research advances that combine micro and nanotechnologies to create the next... 

    Gut-on-a-chip: Current progress and future opportunities

    , Article Biomaterials ; Volume 255 , 2020 Ashammakhi, N ; Nasiri, R ; Barros, N. R. D ; Tebon, P ; Thakor, J ; Goudie, M ; Shamloo, A ; Martin, M. G ; Khademhosseni, A ; Sharif University of Technology
    Elsevier Ltd  2020
    Abstract
    Organ-on-a-chip technology tries to mimic the complexity of native tissues in vitro. Important progress has recently been made in using this technology to study the gut with and without microbiota. These in vitro models can serve as an alternative to animal models for studying physiology, pathology, and pharmacology. While these models have greater physiological relevance than two-dimensional (2D) cell systems in vitro, endocrine and immunological functions in gut-on-a-chip models are still poorly represented. Furthermore, the construction of complex models, in which different cell types and structures interact, remains a challenge. Generally, gut-on-a-chip models have the potential to... 

    Modeling and experimental validation of material flow during FSW of polycarbonate

    , Article Materials Today Communications ; Volume 22 , 2020 Derazkola, H. A ; Eyvazian, A ; Simchi, A ; Sharif University of Technology
    Elsevier Ltd  2020
    Abstract
    Friction stir welding (FSW) of thermoplastic materials is an attractive but a challenging process due to inherent chemical and mechanical characteristics of polymeric materials. In the present work, thermo-mechanical models were employed to investigate the effect of processing parameters on of FSW of polycarbonate (PC). The heat flux during the joining process was localized around the PC join line and led to the formation of circular rings on the upper surface. According to the simulation results, increasing the tool rotational velocity reduced the temperature gradient and decfeased the suseptibelity of crack formation around the joint line. Cracks were formed at low frictional heats and... 

    Friction stir welding of polycarbonate lap joints: Relationship between processing parameters and mechanical properties

    , Article Polymer Testing ; Volume 79 , 2019 ; 01429418 (ISSN) Aghajani Derazkola, H ; Simchi, A ; Lambiase, F ; Sharif University of Technology
    Elsevier Ltd  2019
    Abstract
    The relation between process parameters and properties of polycarbonate (PC) sheet after friction stir welding (FSW) was investigated. Effects of FSW tool rotation speed (ω), travelling speed (V), tilt angle (α) and plunge depth on material flow, joint tensile strength, flexural strength, impact energy and hardness were investigated. It is shown that at low and high levels of heat input sound joints cannot be attained. At low heat inputs, the local temperature is not high enough to decrease the viscosity of the polymer to fill the interface, and thus voids and large planar cracks are formed in the joint root and stir zone. At high heat inputs, expelling of materials due to high peak... 

    An ultrasensitive label free human papilloma virus DNA biosensor using gold nanotubes based on nanoporous polycarbonate in electrical alignment

    , Article Analytica Chimica Acta ; Volume 1048 , 2019 , Pages 31-41 ; 00032670 (ISSN) Shariati, M ; Ghorbani, M ; Sasanpour, P ; Karimizefreh, A ; Sharif University of Technology
    Elsevier B.V  2019
    Abstract
    An impedimetric human papilloma virus (HPV) DNA biosensor based on gold nanotubes (AuNTs) in label free detection was materialized. The AuNTs decorated nanoporous polycarbonate (AuNTs-PC) template as biosensor electrode was fabricated by electrodeposition method. The single strand DNA (ss-DNA) probe was covalently immobilized onto the AuNTs-PC electrode. The hybridization of target sequences with the ss-DNA probe was observed by the electrochemical impedance spectroscopy (EIS). The biosensor showed high selectivity and could differentiate between the complementary, mismatch and non-complementary DNA sequences. The EIS measurements were matched to Randle's equivalent circuit. The... 

    Electrodeposition of well-defined gold nanowires with uniform ends for developing 3D nanoelectrode ensembles with enhanced sensitivity

    , Article Materials Chemistry and Physics ; Volume 213 , 2018 , Pages 67-75 ; 02540584 (ISSN) Bahari Mollamahale, Y ; Ghorbani, M ; Dolati, A ; Hosseini, D ; Sharif University of Technology
    Elsevier Ltd  2018
    Abstract
    Fabrication of well-defined gold nanowires (GNWs) is of significant importance in many fields such as sensing applications. In this study, the electrodeposition of well-defined GNWs inside polycarbonate (PC) template has been discussed in detail. GNWs were potentiostatically electrodeposited at different filling rates. The growth of GNWs at different stages of pore filling was monitored by electrochemical measurements and field-emission scanning electron microscopy (FE-SEM). It was confirmed that under growth rates between 2.5 and 4 nm/s, GNWs with smooth ends grew uniformly inside the template without any imperfections or corrugations. The length of GNWs was electrochemically controlled to... 

    An ultrasensitive label free human papilloma virus DNA biosensor using gold nanotubes based on nanoporous polycarbonate in electrical alignment

    , Article Analytica Chimica Acta ; 2018 ; 00032670 (ISSN) Shariati, M ; Ghorbani, M ; Sasanpour, P ; Karimizefreh, A ; Sharif University of Technology
    Elsevier B.V  2018
    Abstract
    An impedimetric human papilloma virus (HPV) DNA biosensor based on gold nanotubes (AuNTs) in label free detection was materialized. The AuNTs decorated nanoporous polycarbonate (AuNTs-PC) template as biosensor electrode was fabricated by electrodeposition method. The single strand DNA (ss-DNA) probe was covalently immobilized onto the AuNTs-PC electrode. The hybridization of target sequences with the ss-DNA probe was observed by the electrochemical impedance spectroscopy (EIS). The biosensor showed high selectivity and could differentiate between the complementary, mismatch and non-complementary DNA sequences. The EIS measurements were matched to Randle's equivalent circuit. The... 

    Preparation and characterization of polycarbonate/thermoplastic polyurethane blend membranes for wastewater filtration

    , Article Journal of Water Process Engineering ; Volume 16 , 2017 , Pages 170-182 ; 22147144 (ISSN) Nazemidashtarjandi, S ; Mousavi, S. A ; Bastani, D ; Sharif University of Technology
    Elsevier Ltd  2017
    Abstract
    The polycarbonate (PC)/thermoplastic polyurethane (TPU) blend membranes were prepared by phase inversion process applied to membrane bioreactor (MBR) to investigate the fouling characteristics. The impact of TPU and poly (vinylpyrrolidone) PVP concentration in polymer dopes on membrane structure, morphology, and performance were studied. The flat sheet fabricated membranes were characterized by scanning electron microscope (SEM), water contact angle (WCA), membrane surface roughness measurements and mechanical strength. The membrane performance was investigated at subcritical operating conditions. Pure water and critical flux through the fabricated membranes were measured for better... 

    Synthesis and characterization of electrochemically grown CdSe nanowires with enhanced photoconductivity

    , Article Journal of Materials Science: Materials in Electronics ; Volume 26, Issue 3 , March , 2015 , Pages 1395-1402 ; 09574522 (ISSN) Kalhori, H ; Irajizad, A ; Azarian, A ; Ashiri, R ; Sharif University of Technology
    Springer New York LLC  2015
    Abstract
    CdSe nanowires were grown in polycarbonate track etched membrane with pore diameter of 80 nm by an electrochemical deposition technique. The mechanism of the growth was studied during the potentiostatic deposition of nanowires. X-ray photoelectron spectroscopy and energy dispersive spectrometry results showed binding of fragments and fraction of atoms for the CdSe nanowires. Microstructure and morphology of synthesized CdSe nanowires were observed by scanning electron microscopy. Optical spectrophotometry technique was used to determine the energy band gap of CdSe nanowires. It was found that the nanowires were resistive in the dark and exhibited a pronounced visible light photoconductivity.... 

    The potentiostatic electrodeposition of gold nanowire/nanotube in HAuCl4 solutions based on the model of recessed cylindrical ultramicroelectrode array

    , Article Journal of the Electrochemical Society ; Volume 160, Issue 6 , 2013 , Pages D279-D288 ; 00134651 (ISSN) Bagheri Hariri, M ; Dolati, A ; Siavash Moakhar, R ; Sharif University of Technology
    2013
    Abstract
    The mechanism of gold nanowire (AuNW) and nanotube (AuNT) electrodeposition in a cyanide-free solution is investigated for the first time based on the analytical model of Szabo et al. (A. Szabo et al., J. Electroanal. Chem. 217 (1987) 417) for recessed cylindrical ultramicroelectrode (UME). Track-etched Polycarbonate Template (PCT) is served as cylindrical UME ensemble/arrays. Firstly, Au is nucleated through a charge transfer step and when the Nernst thickness exceeds the pore length, the radial diffusion is established around pore mouths. By overlapping of these domains, the planar diffusion toward the whole PCT surface is obtained. An analytic expression for global diffusion coefficient... 

    Electrodeposition of long gold nanotubes in polycarbonate templates as highly sensitive 3D nanoelectrode ensembles

    , Article Electrochimica Acta ; Volume 75 , 2012 , Pages 157-163 ; 00134686 (ISSN) Bahari Mollamahalle, Y ; Ghorbani, M ; Dolati, A ; Sharif University of Technology
    Elsevier  2012
    Abstract
    Electrodeposition of long and well-defined gold nanotubes in polycarbonate (PC) templates is still a major concern due to pore blockage problems. In the present study, we introduce a novel method for electrodeposition of long gold nanotubes within the pores of PC templates for the first time. In order to deposit gold atoms onto the pore walls preferentially, pore walls were functionalized with a coupling agent. Short and thin Ni nanotubes were then electrodeposited at the bottom of the pores. Gold nanotubes were subsequently electrodeposited at constant potentials and low solution concentrations. The morphology of nanotubes was characterized by electron microscopy and their formation... 

    Surface chemistry of atmospheric plasma modified polycarbonate substrates

    , Article Applied Surface Science ; Volume 257, Issue 23 , September , 2011 , Pages 9836-9839 ; 01694332 (ISSN) Yaghoubi, H ; Taghavinia, N ; Sharif University of Technology
    2011
    Abstract
    Surface of polycarbonate substrates were activated by atmospheric plasma torch using different gas pressure, distance from the substrates, velocity of the torch and number of treatments. The modifications were analyzed by contact angle measurements, X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and UV-vis spectrophotometry. Plasma treatment caused the surface characteristics to become more hydrophilic as measured by the water contact angle, which decreased from 88° to 18°. The decrease in contact angle was mainly due to oxidation of the surface groups, leading to formation of polar groups with hydrophilic property. XPS results showed an increase in the intensity of... 

    Electrodeposition of platinum nanowires: Electrochemical characterization

    , Article ECS Transactions, 25 April 2010 through 30 April 2010 ; Volume 28, Issue 18 , April , 2010 , Pages 25-35 ; 19385862 (ISSN) ; 9781607681946 (ISBN) Mahshid, S. S ; Dolati, A ; Hashemi Daryan, S ; Ghorbani, M ; Ghahramaninezhad, A ; Physical and Analytical Electrochemistry ; Sharif University of Technology
    2010
    Abstract
    Platinum nanowires (PtNWs) were electrodeposited on the polycarbonate templates (PCTs) in aqueous solution of H2PtCl6 in triply distilled water. Nanowires with diameters of 50 and 100 nanometers were electrodeposited on the same condition. The kinetics of electrodeposition process was studied by electrochemical techniques such as voltammetry and chronoamperometry methods. Increasing the scan rate, the peaks shifted to more negative potentials and the current density also increased in each peak which was typical for a diffusion-control process. The potential range for the deposition of platinum nanowires was specified and consequently the potentiostatic i-t transients were utilized to produce... 

    A study on the kinetics of gold nanowire electrodeposition in polycarbonate templates

    , Article Journal of Electroanalytical Chemistry ; Volume 645, Issue 1 , June , 2010 , Pages 28-34 ; 15726657 (ISSN) Soleimany, L ; Dolati, A ; Ghorbani, M ; Sharif University of Technology
    2010
    Abstract
    Electrodeposition of gold nanowires is carried out in cyanide solution in polycarbonate templates with pore diameter of 80 nm. Electrochemical methods are utilized to characterize the gold electrodeposition and to obtain the nucleation and growth mechanism. The analysis of cyclic voltammograms shows that the electrodeposition of gold nanowires takes place under diffusion control. Current transients reveal that nucleation mechanism is instantaneous with a three-dimensional growth process. The transition-time measurements show that the gold elecrodeposition occurs as one-electron valence involved in the reaction mechanism. Charge transfer coefficient is also found to be 0.67 ± 0.01. The value... 

    Field emission of Co nanowires in polycarbonate template

    , Article Thin Solid Films ; Volume 517, Issue 5 , 1 January , 2009 , Pages 1736-1739 ; 00406090 (ISSN) Azarian, A ; Iraji Zad, A ; Dolati, A ; Mahdavi, S. M ; Sharif University of Technology
    2009
    Abstract
    The Co nanowire arrays were synthesized by electrodeposition in polycarbonate template (PC) with 4 μm thickness. Electron field emission properties of cobalt nanowires were studied for wires with different aspect ratios, R ranged between 10 and 60, while the diameter of wires was fixed about 50 nm. The field emission properties of the samples showed low turn on electric field (Eto) with values varying between 2.9 and 11.3 V/μm showing a minimum value for R = 20 (Eto < 3 V/μm). On the other hand, the enhancement factor shows a peak for nanowires length about 1 μm. Field emission data using the Fowler-Nordhiem theory showed nearly straight-line nature confirming cold field emission of... 

    Polycarbonate surface cell's adhesion examination after Nd:YAG laser irradiation

    , Article Materials Science and Engineering C ; Volume 29, Issue 4 , 2009 , Pages 1491-1497 ; 09284931 (ISSN) Ramezani Saadat Abadi, A ; Mousavi, A ; Seyedjafari, E ; Poursalehi, R ; Sareh, S ; Silakhori, K ; Poorfatollah, A. A ; Shamkhali, A. N ; Sharif University of Technology
    2009
    Abstract
    Nd:YAG laser treatment was used in order to increase surface cell adhesion aspects of polycarbonate (PC) films prepared via melt process. The treatment was carried out under different wavelengths and beam diameters. ATR-FTIR and UV spectra obtained from different samples before and after laser treatment in air showed that laser irradiation has induced some chemical and physical changes in surface properties. The irradiated films were also characterized using scanning electron microscopy (SEM) and contact angle measurements. Effect of pulse numbers on the surface properties was also investigated. Cell culture test was used to evaluate cell adhesion property on the PC films before and after... 

    Surface plasmon resonance of two-segmented Au-Cu nanorods

    , Article Nanotechnology ; Volume 19, Issue 41 , 2008 ; 09574484 (ISSN) Azarian, A ; Iraji Zad, A ; Dolati, A ; Ghorbani, M ; Sharif University of Technology
    2008
    Abstract
    Two-segmented gold-copper nanorods were electrodeposited inside the pores of polycarbonate track-etched membranes from two separate solutions. The PCT membranes were dissolved in dichloromethane (CH2Cl2) and the solvent was replaced by methanol solution. Optical absorption spectra of two-segmented Au-Cu nanorods dispersed in methanol showed two peaks which were related to the transverse mode of copper and the longitudinal mode of gold. By increasing the length of the gold segment, when the total length of both metals was fixed at 1 μm, the copper and gold peaks shifted to the blue and red wavelengths, respectively. We observed that the wavelengths of the extinction peaks are not in good... 

    Time dependence of the surface plasmon resonance of copper nanorods

    , Article Journal of Physics Condensed Matter ; Volume 19, Issue 44 , 2007 ; 09538984 (ISSN) Azarian, A ; Iraji zad, A ; Dolati, A ; Ghorbani, M ; Sharif University of Technology
    2007
    Abstract
    Copper nanorods have been synthesized by electrodeposition with different lengths in porous polycarbonate (PCT) membranes with a pore diameter of 50nm and a thickness of 4νm. The PCT membranes were dissolved in dichloromethane (CH2Cl2) and the solvent was replaced by methanol solutions. Extinction peaks at 587, 581 and 574nm were observed for the Cu nanorods with aspect ratio R = 6,8 and 10 in methanol, respectively. Polarization of the molecules of the medium around the wires changes the dielectric constant of the medium. Hence, the wavelength of the extinction peaks does not shows good agreement with calculations that were done on basis of Gans' theory with nominal dielectric constant of...