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    Capping antibacterial Ag nanorods aligned on Ti interlayer by mesoporous TiO2 layer

    , Article Surface and Coatings Technology ; Volume 203, Issue 20-21 , 2009 , Pages 3123-3128 ; 02578972 (ISSN) Akhavan, O ; Ghaderi, E ; Sharif University of Technology
    In this work, aligned and compact Ag nanorods capped by sol-gel mesoporous TiO2 layer were grown on Ti/Si(100) in order to be applied in antibacterial applications. The Ag nanorods with a high effective surface were grown by applying an electric field perpendicular to the surface of the Ag/Ti/Si thin film while it was being heat-treated at 700 °C in an Ar + H2 ambient. The grown silver nanorods had widths and lengths of 20-50 and 250-500 nm with an abundance in {100} facet, respectively. The TiO2 cap layer also had the specific surface area, the total pore volume and the pore diameter of 474 m2/g, 0.49 cm3/g and 8.0 nm, respectively. Antibacterial activities of the TiO2-capped Ag nanorods... 

    Biodegradation of synthetic dye using partially purified and characterized laccase and its proposed mechanism

    , Article International Journal of Environmental Science and Technology ; Volume 16, Issue 12 , 2019 , Pages 7805-7816 ; 17351472 (ISSN) Ghobadi Nejad, Z ; Borghei, S. M ; Yaghmaei, S ; Sharif University of Technology
    Center for Environmental and Energy Research and Studies  2019
    The supernatant obtained from the extracellular laccase produced by Phanerochaete chrysosporium was used as the enzyme source to conduct a partial purification, characterization and dye decolorization study. The partially purified enzyme was stable in the pH range of 3–5 and showed an optimum activity at pH 4.0, using guaiacol as a substrate. Laccase stability of pH was determined and discovered to retain 100% of its activity at a pH of 4.0 after 2 h. The maximum enzyme activity was obtained between 30 and 50 °C. The maximum velocity and Michaelis constant were calculated as 3.171 µM−1·min and 1628.23 µM, respectively. The enzyme was activated by Fe2+, Zn2+, Ca2+ and Cu2+, while Hg2+, Mn2+,... 

    Improvement of the microfluidic microbial fuel cell using a nickel nanostructured electrode and microchannel modifications

    , Article Journal of Power Sources ; Volume 437 , 2019 ; 03787753 (ISSN) Mousavi, M. R ; Ghasemi, S ; Sanaee, Z ; Ghobadi Nejad, Z ; Mardanpour, M. M ; Yaghmaei, S ; Ghorbanzadeh, M ; Sharif University of Technology
    Elsevier B.V  2019
    In this study, the effect of utilization of a nanostructured nickel based material as a negative electrode on the performance of microfluidic microbial fuel cell (MFC) with Escherichia coli as biocatalyst has been investigated. Designing the microfluidic MFC with nickel nanostructure resulted in a higher volumetric power density of 343 W m−3 compared to the previously published results. The assessment of effective parameters on the electrochemical performance of cell was investigated. The investigation of the hydraulic diameter impact on the power generation proves that reducing the microchannel hydraulic diameter from 1000 to 350 μm minimized the internal mass-transfer resistance, and... 

    Solar-assisted bacterial disinfection and removal of contaminants of emerging concern by Fe2+-activated HSO5- vs. S2O82- in drinking water

    , Article Applied Catalysis B: Environmental ; Volume 248 , 2019 , Pages 62-72 ; 09263373 (ISSN) Rodríguez Chueca, J ; Giannakis, S ; Marjanovic, M ; Kohantorabi, M ; Gholami, M. R ; Grandjean, D ; de Alencastro, L. F ; Pulgarín, C ; Sharif University of Technology
    Elsevier B.V  2019
    This research demonstrates the feasibility to enhance solar disinfection (SODIS) treatment by addition of peroxymonosulfate (PMS) and peroxydisulfate (PDS) by the generation of sulfate (and hydroxyl) radicals through different activation routes. The different promoters were i) sunlight irradiation, ii) mild heat (40 °C), and iii) μM amounts of Fe2+, all present during actual field SODIS experiments, or voluntarily added alongside PMS/PDS. In a first approach, the promoters were studied separately, in pairs and finally all together in a combined process (CP). In all the cases, PMS showed a higher efficiency than PDS in E. coli removal, requiring lower concentration and a faster reaction time... 

    A systematic investigation on the bactericidal transient species generated by photo-sensitization of natural organic matter (NOM) during solar and photo-Fenton disinfection of surface waters

    , Article Applied Catalysis B: Environmental ; Volume 244 , 2019 , Pages 983-995 ; 09263373 (ISSN) Kohantorabi, M ; Giannakis, S ; Gholami, M. R ; Feng, L ; Pulgarin, C ; Sharif University of Technology
    Elsevier B.V  2019
    In this work, the role of dissolved oxygen in the solar and the photo-Fenton-mediated E. coli inactivation process was put under scrutiny. The effect of transient species that were produced in the presence of various natural organic matter isolates (NOM), namely Suwannee River (SR) NOM, Nordic Reservoir (NR) NOM, SR Humic acid (SRHA), and SR Fulvic acid (SRFA) was studied in detail. The role of 1 O2 in this reaction was systematically evaluated by modifying the O2 concentration (N2/O2 purging) and the matrix composition (10, 50, and 100% deuterium oxide (D2O) v/v). In the presence of NOM, 1 O2 was generated and the enhancement of E. coli inactivation rate due to charge transfer from triplet... 

    Sustained release of CIP from TiO2-PVDF/starch nanocomposite mats with potential application in wound dressing

    , Article Journal of Applied Polymer Science ; Volume 137, Issue 30 , 2020 Ansarizadeh, M ; Haddadi, S. A ; Amini, M ; Hasany, M ; Ramazani SaadatAbadi, A ; Sharif University of Technology
    John Wiley and Sons Inc  2020
    Electrospinning is an economical and alluring method to fabricate wound dressing mats from a variety of natural and synthetic materials. In this study, polyvinylidene fluoride (PVDF) and starch composite mats containing ciprofloxacin (CIP) loaded on titanium dioxide nanoparticles (TiO2) were prepared. Fourier Transform Infrared spectra of CIP, synthesized TiO2 NPs, TiO2/CIP, and PVDF/starch composite mats are analyzed. Scanning electron microscopy images revealed that the fiber diameter of PVDF nanofibers thickens by increasing starch, which varies between 180 nm and 550 nm. Strain at break of PVDF, starch, PVDF/starch (2:1 w:w; P2S1), PVDF/starch (1:1 w:w; P1S1), PVDF/starch (1:2 w:w;... 

    The coupled microfluidic microbial electrochemical cell as a self-powered biohydrogen generator

    , Article Journal of Power Sources ; Volume 451 , 2020 Fadakar, A ; Mardanpour, M. M ; Yaghmaei, S ; Sharif University of Technology
    Elsevier B.V  2020
    Due to the importance of hydrogen as an effective antioxidant for its applications in therapy, this research reports the fabrication of a coupled microfluidic microbial electrochemical cell (MXC), including microfluidic microbial fuel cells (MFCs) and a microfluidic microbial electrolysis cell (MEC) series in order to perform it as a self-powered biohydrogen generator. Being able to be a platform of implantable medical devices, utilization a non-phatogenic strain of Escherichia coli as the biocatalyst in order to exploit the embodied energy from human blood and excrement and finally the use of cheap and facile materials (<$2 per device) are the exceptional features of the system. The... 

    Design and application of (Fe3O4)-GOTfOH based AgNPs doped starch/PEG-poly (acrylic acid) nanocomposite as the magnetic nanocatalyst and the wound dress

    , Article Journal of Molecular Structure ; Volume 1214 , 2020 Forouzandehdel, S ; Meskini, M ; Rami, M. R ; Sharif University of Technology
    Elsevier B.V  2020
    As a novel, recyclable nanocatalyst, (Fe3O4)-GOTfOH based Ag nanoparticles doped Starch/PEG-poly (acrylic acid) nanocomposite (Fe3O4@GOTfOH/Ag/St-PEG-AcA) was applied for one-pot synthesis of 2,4,6-triarylpyridine derivatives under water solvent conditions. The prepared nanocomposite was also evaluated in terms of biocompatibility for wound healing. Fe3O4@GOTfOH/Ag/St-PEG-AcA could be easily removed from the mixture of the reaction by an external magnet and recycled without a considerable decrease of activity even after 10 runs. The new nanocatalyst offered better efficiencies than other commercially available sulfonic acid catalysts. In terms of the bioactivity of nanocatalyst, good... 

    Optimization and characterization of tannic acid loaded niosomes for enhanced antibacterial and anti-biofilm activities

    , Article Advanced Powder Technology ; 2020 Heidari, F ; Akbarzadeh, I ; Nourouzian, D ; Mirzaie, A ; Bakhshandeh, H ; Sharif University of Technology
    Elsevier B.V  2020
    The purpose of this study was to prepare and characterize an optimized system of tannic acid-loaded niosomes as a potential carrier for antibacterial and anti-biofilm delivery. The niosomal formulation was optimized using response surface methodology (RSM). The effects of the molar ratio of surfactant to cholesterol, drug concentration, and molar ratio of Span 60 to Tween 60 on particle size and drug entrapment efficiency of the niosomal nanocarrier were studied. The optimized nanoparticles were characterized in terms of the morphology, in vitro release profile, and antibacterial properties. Moreover, Fourier-transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC)... 

    Effects of SiC nanoparticles on synthesis and antimicrobial activity of TiCu nanocrystalline powder

    , Article Ceramics International ; Volume 46, Issue 1 , January , 2020 , Pages 114-120 Moniri Javadhesari, S ; Alipour, S ; Akbarpour, M. R ; Sharif University of Technology
    Elsevier Ltd  2020
    Effects of SiC nanoparticles addition on synthesis and antibacterial properties of TiCu nanocrystalline powder prepared through high energy mechanical milling were studied. The results showed that the synthesis of TiCu powder in the presence of the nanoparticles was accelerated and after mechanical alloying for 20 h, a TiCu/SiC nanocrystalline powder with the crystallite size <5 nm, and 3.3% lattice micro-strain obtained. Further milling resulted in fully amorphous TiCu intermetallic alloy with more uniform distribution of SiC nanoparticles. The antibacterial activity of the synthesized powders was investigated by disk diffusion test. The TiCu/SiC nanocomposites showed enhanced antibacterial... 

    Synergistic enhancement of photocatalytic antibacterial effects in high-strength aluminum/TiO2 nanoarchitectures

    , Article Ceramics International ; Volume 46, Issue 15 , October , 2020 , Pages 24267-24280 Mesbah, M ; Sarraf, M ; Dabbagh, A ; Nasiri Tabrizi, B ; Paria, S ; Banihashemian, S. M ; Bushroa, A. R ; Faraji, G ; Tsuzuki, T ; Madaah Hosseini, H. R ; Sharif University of Technology
    Elsevier Ltd  2020
    Unlike gold and silver, aluminum shows a localized surface plasmon resonance (LSPR) over a wide spectral range from ultraviolet (UV) to the visible region. Herein, we demonstrate a new process to optically couple TiO2 nanotubes (NTs) with a high-strength aluminum substrate, to achieve a synergistic enhancement of photocatalytic antibacterial effects through controlled LSPR of aluminum. The high-strength aluminum substrate was produced by tubular channel angular pressing (TCAP). Their LSPR was tailored through the formation of superficial nano-concave arrays (NCAs) with desired concave diameters. A layer of aligned TiO2 NTs was fabricated on the surface of aluminum nano-concave arrays (Al... 

    Synthesis of nanobentonite–poly(vinyl alcohol)–bacterial cellulose nanocomposite by electrospinning for wound healing applications

    , Article Physica Status Solidi (A) Applications and Materials Science ; Volume 217, Issue 6 , 2020 Zeaiean Firouzabadi, P ; Ghanbari, H ; Mahmoudi, N ; Haramshahi, S. M. A ; Javadpour, J ; Sharif University of Technology
    Wiley-VCH Verlag  2020
    Polymer-based composites are used for wound healing applications. This work aims to prepare an inorganic-polymer nanocomposite based on bentonite, poly(vinyl alcohol), and bacterial cellulose by electrospinning for wound healing. The nanocomposite is synthesized using a solution intercalation technique, with 1–2 wt% nanobentonite concentration variation. The effects of commercial and laboratory-synthesized nanobentonite as well as the extract of the green walnut shell (EGWS) are examined and characterized by different techniques. The addition of nanobentonite increases the average size of fibers and tensile strength up to 200 nm and more than 15 MPa, respectively, due to the presence of... 

    The performances of the chi-square test and complexity measures for signal recognition in biological sequences

    , Article Journal of Theoretical Biology ; Volume 251, Issue 2 , 2008 , Pages 380-387 ; 00225193 (ISSN) Pirhaji, L ; Kargar, M ; Sheari, A ; Poormohammadi, H ; Sadeghi, M ; Pezeshk, H ; Eslahchi, C ; Sharif University of Technology
    With large amounts of experimental data, modern molecular biology needs appropriate methods to deal with biological sequences. In this work, we apply a statistical method (Pearson's chi-square test) to recognize the signals appear in the whole genome of the Escherichia coli. To show the effectiveness of the method, we compare the Pearson's chi-square test with linguistic complexity on the complete genome of E. coli. The results suggest that Pearson's chi-square test is an efficient method for distinguishing genes (coding regions) form pseudogenes (noncoding regions). On the other hand, the performance of the linguistic complexity is much lower than the chi-square test method. We also use the... 

    Apatite-coated Ag/AgBr/TiO2 visible-light photocatalyst for destruction of bacteria

    , Article Journal of the American Chemical Society ; Volume 129, Issue 31 , 2007 , Pages 9552-9553 ; 00027863 (ISSN) Elahifard, M. R ; Rahimnejad, S ; Haghighi, S ; Gholami, M. R ; Sharif University of Technology
    Apatite-coated Ag/AgBr/TiO2 was prepared by deposition of Ag as novel metal to generate electron-hole pairs by extending the excitation wavelength to the visible-light region, AgBr, and hydroxy apatite as photosensitive material and adsorption bioceramic, respectively. The energy dispersive X-ray spectrometry clearly showed the presence of Ti, Ag, Ca, and P elements on the surface of catalyst. The bactericidal experiments in dark media indicated that only the novel catalyst shows inhibiting growth of bacteria in this case. A transmission electron microscopy image illustrated that catalyst nanoparticles adhere to the outer membrane of the cell and act as an inhibitor to the nourishment of... 

    PLGA/TiO2 nanocomposite scaffolds for biomedical applications: Fabrication, photocatalytic, and antibacterial properties

    , Article BioImpacts ; Volume 11, Issue 1 , 2021 , Pages 45-52 ; 22285652 (ISSN) Pelaseyed, S. S ; Madaah Hosseini, H. R ; Nokhbedehghan, Z ; Samadikuchaksaraei, A ; Sharif University of Technology
    Tabriz University of Medical Sciences  2021
    Introduction: Porous 3D scaffolds synthesized using biocompatible and biodegradable materials could provide suitable microenvironment and mechanical support for optimal cell growth and function. The effect of the scaffold porosity on the mechanical properties, as well as the TiO2 nanoparticles addition on the bioactivity, antimicrobial, photocatalytic, and cytotoxicity properties of scaffolds were investigated. Methods: In the present study, porous scaffolds consisting poly (lactide-co-glycolide) (PLGA) containing TiO2 nanoparticles were fabricated via air-liquid foaming technique, which is a novel method and has more advantages due to not using additives for nucleation compared to former... 

    Evaluation of antibacterial behavior of in situ grown CuO-GO nanocomposites

    , Article Materials Today Communications ; Volume 28 , 2021 ; 23524928 (ISSN) Ahmadi, R ; Fattahi Nafchi Fatahi, R ; Sangpour, P ; Bagheri, M ; Rahimi, T ; Sharif University of Technology
    Elsevier Ltd  2021
    The growth of harmful microorganisms is a severe threat to human life. Nowadays, it is necessary to prepare antimicrobials materials with high biocompatibility properties. Hence, the use of nanomaterials and their nanocomposites has been proposed as a suitable way to obtain safe and potent antibacterial materials. Recently, several studies have been conducted on the antibacterial properties of metal oxide and graphene oxide (GO) nanomaterials individually. This study investigated the synergistic effect of GO and copper oxide (CuO) as a nanocomposite. CuO-GO nanocomposite containing 5%, 15%, 25%, 50%, and 75% of GO were synthesized to study antibacterial properties. X-ray diffraction (XRD)... 

    Effect of graphene oxide nanosheets on visible light-assisted antibacterial activity of vertically-aligned copper oxide nanowire arrays

    , Article Journal of Colloid and Interface Science ; Volume 521 , 2018 , Pages 119-131 ; 00219797 (ISSN) Kiani, F ; Ashari Astani, N ; Rahighi, R ; Tayyebi, A ; Tayebi, M ; Khezri, J ; Hashemi, E ; Rothlisberger, U ; Simchi, A ; Sharif University of Technology
    Academic Press Inc  2018
    In the present work, the effect of graphene oxide (GO) nanosheets on the antibacterial activity of CuO nanowire arrays under visible light irradiation is shown. A combined thermal oxidation/electrophoretic deposition technique was employed to prepare three-dimensional networks of graphene oxide nanosheets hybridized with vertically aligned CuO nanowires. With the help of standard antibacterial assays and X-ray photoelectron spectroscopy, it is shown that the light-activated antibacterial response of the hybrid material against gram-negative Escherichia coli is significantly improved as the oxide functional groups of the GO nanosheets are reduced. In order to explore the physicochemical... 

    Lasting antibacterial activities of Ag-TiO2/Ag/a-TiO2 nanocomposite thin film photocatalysts under solar light irradiation

    , Article Journal of Colloid and Interface Science ; Volume 336, Issue 1 , 2009 , Pages 117-124 ; 00219797 (ISSN) Akhavan, O ; Sharif University of Technology
    Photodegradation of Escherichia coli bacteria in presence of Ag-TiO2/Ag/a-TiO2 nanocomposite film with an effective storage of silver nanoparticles was investigated in the visible and the solar light irradiations. The nanocomposite film was synthesized by sol-gel deposition of 30 nm Ag-TiO2 layer on ∼200 nm anatase(a-)TiO2 film previously doped by silver nanoparticles. Both Ag/a-TiO2 and Ag-TiO2/Ag/a-TiO2 films were transparent with a SPR absorption band at 412 nm. Depth profile X-ray photoelectron spectroscopy showed metallic silver nanoparticles with diameter of 30 nm and fcc crystalline structure were self-accumulated on the film surface at depth of 5 nm of the TiO2 layer and also at the... 

    Enhanced electricity generation from whey wastewater using combinational cathodic electron acceptor in a two-chamber microbial fuel cell

    , Article International Journal of Environmental Science and Technology ; Volume 9, Issue 3 , 2012 , Pages 473-478 ; 17351472 (ISSN) Nasirahmadi, S ; Safekordi, A. A ; Sharif University of Technology
    While energy consumption is increasing worldwide due to population growth, the fossil fuels are unstable and exhaustible resources for establishing sustainable life. Using biodegradable compounds present in the wastewater produced in industrial process as a renewable source is an enchanting approach followed by scientists for maintaining a sustainable energy production to vanquish this problem for ulterior generations. In this research, bioelectricity generation with whey degradation was investigated in a two-chamber microbial fuel cell with humic acid as anodic electron mediator and a cathode compartment including combinational electron acceptor. Escherichia coli was able to use the... 

    Silver nanoparticles with gelatin nanoshells: Photochemical facile green synthesis and their antimicrobial activity

    , Article Journal of Nanoparticle Research ; Volume 13, Issue 10 , October , 2011 , Pages 4647-4658 ; 13880764 (ISSN) Pourjavadi, A ; Soleyman, R ; Sharif University of Technology
    In the current study, a facile green synthesis of silver-gelatin core-shell nanostructures (spherical, spherical/cubic hybrid, and cubic, DLS diameter: 4.1-6.9 nm) is reported via the wet chemical synthesis procedure. Sunlight-UV as an available reducing agent cause mild reduction of silver ions into the silver nanoparticles (Ag-NPs). Gelatin protein, as an effective capping/shaping agent, was used in the reaction to self-assemble silver nanostructures. The formation of silver nanostructures and their self-assembly pattern was confirmed by SEM, AFM, and TEM techniques. Further investigations were carried out using zeta-potential, UV-Vis, FTIR, GPC, and TGA/DTG/DTA data. The prepared Ag-NPs...