Synthesis, characterization and performance enhancement of dry polyaniline-coated neuroelectrodes for electroencephalography measurement

Aghazadeh Hadiseh,Yazdi Mohsen Khodadadi,Kolahi Alireza,Yekani Milad,Zarrintaj Payam,Ramsey Joshua D.,Ganjali Mohammad Reza,Stadler Florian J.,Saeb Mohammad Reza,Mozafari Masoud 한국물리학회 2021 Current Applied Physics Vol.27 No.-

Originating from a combination of neuroscience and biomedical engineering strategies, neuroprosthetics are developed as substitutes for sensory or cognitive modality damages caused by an injury or a disease. Dry electrodes are essential devices for monitoring of the biopotential such as electroencephalography (EEG) and electrocardiography (ECG). In this paper, polyaniline (PANI) coated stainless steel (SS) electrodes have been fabricated using in-situ electrochemical polymerization on the SS surface. The SEM images showed the formation of a nanoporous PANI-coating on the SS electrodes. EIS measurements on a skin model demonstrated a significantly lower contact impedance for the PANI-coated electrodes compared to bare SS electrodes. Furthermore, increasing the thickness of the nanoporous coating resulted in a higher contact impedance reduction. The comparison of the EEG measurements for the manufactured electrodes with conventional wet Ag/AgCl electrodes showed that the electrodes could successfully monitor alpha rhythms and muscle artifacts, as well. The prepared electrode can be used in various applications such as biopotential monitoring.

Gd3+ doped Fe3O4 nanoparticles with proper magnetic and supercapacitive characteristics: A novel synthesis platform and characterization

Mustafa Aghazadeh,Isa Karimzadeh,Mohammad Ghannadi-Maragheh,Mohammad Reza Ganjali 한국화학공학회 2018 Korean Journal of Chemical Engineering Vol.35 No.6

A novel electrochemical procedure was developed for the facile preparation of Gd-doped iron oxide nanoparticles (GdIO-NPs). A simple galvanostatic deposition (i=10mA cm2) was done in an additive-free aqueous solution containing FeCl2·4H2O, Fe(NO3)3·9H2O and GdCl3·6H2O. The XRD, FE-SEM, EDS and TEM characterizations showed that the product is composed of 15% GdIO-NPs with 10 nm in size. VSM analysis proved that the GdIONPs are superparamagnetic. The cyclic voltammetry and charge-discharge tests showed that the prepared GdIO-NPs are capable to deliver specific capacity as high as 190.1 F g1 at 0.5A g1 and capacity retention of 95.1% after 2000 cycling. Based on the results, it was concluded that the developed electrochemical strategy acts as an efficient procedure for the preparation of lanthanide doped MNPs with proper magnetic and supercapacitive characters.

The Effect of Melanocyte Stimulating Hormone and Hydroxyapatite on Osteogenesis in Pulp Stem Cells of Human Teeth Transferred into Polyester Scaffolds

Marziyeh Aghazadeh,Mohammad Samiei,Vahideh Raeisdasteh Hokmabad,Effat Alizadeh,Neda Jabbari,Alexander Seifalian,Roya Salehi 한국섬유공학회 2018 Fibers and polymers Vol.19 No.11

Presently, tissue engineering is employed in the restoration and repair of tissue defects. Degradable scaffolds, stem cells and stimulating factors are employed in this method. In this study, the effect of melanocyte-stimulating hormone (MSH) and/or hydroxyapatite (HA) on proliferation, osteoblast differentiation, and mineralization of human dental pulp stem cells (hDPSCs) seeded on PLLA-PCL nanofibrous scaffolds was evaluated. For this aim, PLLA-PCL-HA nanofibrous scaffolds were fabricated using electrospinning method. FE-SEM images exhibited that all nanofibers had bead-free morphologies with average diameters ranging from 150-205 nm. Human DPSCs seeded into PLLA-PCL nanofibers were treated with MSH. Cell viability, proliferation, morphology, osteogenic potential, and the expression of tissue-specific genes were assessed by means of MTT assay, FE-SEM, alizarin red S staining, and RT-PCR analysis. hDPSCs exhibited improved adhesion and proliferation capacity on the PLLA-PCL-HA nanofibers treated with MSH compared to other groups (p<0.05). Additionally, PLLA-PCL-HA nanofibers treated with MSH exhibited significantly higher mineralization and alkaline phosphatase activity than other groups. RT-PCR results confirmed that PLLA-PCL-HA nanofibers enriched with MSH could significantly unregulated the gene expression of BMP2, osteocalcin, RUNX2 and DSPP that correlated to osteogenic differentiation (p<0.05). Based on results, incorporation of HA nanoparticles in PLLA-PCL nanofibers and addition of MSH in media exhibited synergistic effects on the adhesion, proliferation, and osteogenesis differentiation of hDPSCs, and therefore assumed to be a favorable scaffold for bone tissue engineering applications.

High Performance Electrode Material for Supercapacitors Based on α-Co(OH)2 Nano-Sheets Prepared Through Pulse Current Cathodic Electro-Deposition (PC-CED)

Mustafa Aghazadeh,Amir Rashidi,Mohammad Reza Ganjali 대한금속·재료학회 2018 ELECTRONIC MATERIALS LETTERS Vol.14 No.1

In this paper, the well-defined nano-sheets of α-Co(OH)2 were preparedthrough the cathodic electrosynthesis from an additive-free aqueous cobaltnitrate bath. The pulse current cathodic electro-deposition (PC-CED) was usedas the means for the controlling the OH− electrogeneration on the cathodesurface. The characteristics and electrochemical behavior of the prepared cobalthydroxide were also assessed through SEM, TEM, XRD, BET, and IR. Theresults proved the product to be composed of crystalline pure α phase of cobalthydroxide with sheet-like morphology at nanoscale. Evaluations of theelectrochemical behaviour of the α-Co(OH)2 nano-sheets revealed that they arecapable to delivering the specific capacitance of 1122 F g−1 at a discharge loadof 3 A g−1 and SC retention of 84% after 4000 continues discharging cycles,suggesting the nano-sheets as promising candidates for use in electrochemicalsupercapacitors. Further, the method used for the preparation of the compoundsenjoys the capability of being scaled up.

Genotypic Diversity of Multidrug Resistant Shigella species from Iran

Sajjad Zamanlou,Mohammad Ahangarzadeh Rezaee,Mohammad Aghazadeh,Reza Ghotaslou,Hossein Hosseini Nave,Younes Khalili 대한감염학회 2018 Infection and Chemotherapy Vol.50 No.1

Background: In many developing countries, shigellosis is endemic and also occurs in epidemics and treatment of multidrug-resistant (MDR) isolates are important. The aims of this study were to determine the antimicrobial susceptibility, prevalence of class 1 and 2 integrons and the clonal relatedness of isolates. Materials and Methods: Antimicrobial susceptibility tests were performed by disc diffusion method. Polymerase chain reaction (PCR)-sequencing technique was employed for detection and characterization of integrons. The genetic relatedness was evaluated by using enterobacterial repetitive intergenic consensus (ERIC) PCR. Results: There was a high percentage of resistance to trimethoprim-sulfamethoxazole (TMP/SMX) (93.7%), ampicillin (AMP) (87.3%), streptomycin (STR) (84.5%) and tetracycline (TET) (78.9%). MDR phenotype was seen in 95.1% of total isolates. Most common MDR profile was TMP/SMX/STR/AMP resistant pattern. Among the 142 Shigella spp. analyzed in this study, 28 isolates were positive for class 1 integron with two types of gene cassette arrays (dfrA17/aadA5 = 31.7% and dfrA7 = 3.8%). The class 2 integron was more frequently detected among the isolates (94.7%) with dfrA1/sat1/aadA1 (69.4%) and dfrA1/sat1 (30.6%) gene cassettes. ERIC-PCR results showed 6, 5, 4 and 3 main genotypes among S. flexneri, S. sonnei, S. boydii and S. dysenteriae isolates, respectively. Conclusion: Our findings revealed that multidrug resistant Shigella species with high prevalence of class 2 integron were very common in Iran. In addition, ERIC-PCR patterns showed limited variety of clones are responsible for shigellosis in the region of the study.

Template-free synthesis of MnO2 nanowires with secondary flower like structure: Characterization and supercapacitor behavior studies

Taher Yousefi,Ahmad Nozad Golikand,Mohammad Hossein Mashhadizadeh,Mustafa Aghazadeh 한국물리학회 2012 Current Applied Physics Vol.12 No.1

Manganese dioxide (MnO2) nanowires with diameter about 30e70 nm is achieved via a two-step process: first, template-free cathodic electrodeposition from aqueous solution of Mn(NO3)2 on steel substrate and followed by heat treatment. The temperature-annealed sample was studied by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM)methods and Fourier transform infrared (FT-IR) spectroscopy. The electrochemical performance of the MnO2 sample was studied by cyclic voltammetry (CV) and chronopotentiometry in Na2SO4 solutions. The sample showed excellent supercapacitive behavior. The specific capacitance (SC) of 237 F g-1 in a potential window of 0e0.9V was obtained at the scan rate of 2 mV s-1. The SC calculated from the chronopotentiometry data is about 246 F g-1. The SC was decreased by 16% after 1000 cycles. Manganese dioxide (MnO2) nanowires with diameter about 30e70 nm is achieved via a two-step process: first, template-free cathodic electrodeposition from aqueous solution of Mn(NO3)2 on steel substrate and followed by heat treatment. The temperature-annealed sample was studied by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM)methods and Fourier transform infrared (FT-IR) spectroscopy. The electrochemical performance of the MnO2 sample was studied by cyclic voltammetry (CV) and chronopotentiometry in Na2SO4 solutions. The sample showed excellent supercapacitive behavior. The specific capacitance (SC) of 237 F g-1 in a potential window of 0e0.9V was obtained at the scan rate of 2 mV s-1. The SC calculated from the chronopotentiometry data is about 246 F g-1. The SC was decreased by 16% after 1000 cycles.

High temperature and low current density synthesis of Mn3O4 porous nano spheres: Characterization and electrochemical properties

Taher Yousefi,Ahmad Nozad Golikand,Mohammad Hossein Mashhadizadeh,Mustafa Aghazadeh 한국물리학회 2012 Current Applied Physics Vol.12 No.2

Uniform and single-crystalline Mn3O4 nano-spheres were synthesized by cathodic electrodeposition at high temperature (80 ℃) and low current density (0.25 mA cm-1) on steel electrode. Further the annealed samples were characterized for their structural and morphological properties by means of Xray diffraction (XRD), Fourier transform infrared spectrum (FTIR), Scanning electron microscopy (SEM),Transmission electron microscopy (TEM) and Brunauer-Emmett-Teller (BET) studies. TEM and SEM images showed that particles have spherical shapes and the average diameter size was about 50 nm. Formation of Mn3O4 compound was confirmed from FTIR studies. The XRD pattern showed that the Mn3O4 exhibit tetragonal hausmannite structure. The results of N2 adsorption-desorption analysis indicated that Mn3O4 nanoesphere has BET surface area of about 177.6 m2 g-1 and average pore diameters of 3 and 4 nm. The possible formation mechanism of Mn3O4 nanostructures has been discussed. The supercapacitive properties of Mn3O4 sample in 0.5 M Na2SO4 electrolyte showed maximum supercapacitance of 235.4 Fg-1 at scan rate 10 mV s-1. Coulumbic efficiency could be kept about 90%during 1000 cycles at 10 mV s-1. Uniform and single-crystalline Mn3O4 nano-spheres were synthesized by cathodic electrodeposition at high temperature (80 ℃) and low current density (0.25 mA cm-1) on steel electrode. Further the annealed samples were characterized for their structural and morphological properties by means of Xray diffraction (XRD), Fourier transform infrared spectrum (FTIR), Scanning electron microscopy (SEM),Transmission electron microscopy (TEM) and Brunauer-Emmett-Teller (BET) studies. TEM and SEM images showed that particles have spherical shapes and the average diameter size was about 50 nm. Formation of Mn3O4 compound was confirmed from FTIR studies. The XRD pattern showed that the Mn3O4 exhibit tetragonal hausmannite structure. The results of N2 adsorption-desorption analysis indicated that Mn3O4 nanoesphere has BET surface area of about 177.6 m2 g-1 and average pore diameters of 3 and 4 nm. The possible formation mechanism of Mn3O4 nanostructures has been discussed. The supercapacitive properties of Mn3O4 sample in 0.5 M Na2SO4 electrolyte showed maximum supercapacitance of 235.4 Fg-1 at scan rate 10 mV s-1. Coulumbic efficiency could be kept about 90%during 1000 cycles at 10 mV s-1.

Pulmonary Tuberculosis Diagnosis: Where We Are?

( Hamed Ebrahimzadeh Leylabadlo ),( Hossein Samadi Kafil ),( Mehdi Yousefi ),( Mohammad Aghazadeh ),( Mohammad Asgharzadeh ) 대한결핵 및 호흡기학회 2016 Tuberculosis and Respiratory Diseases Vol.79 No.3

In recent years, in spite of medical advancement, tuberculosis (TB) remains a worldwide health problem. Although many laboratory methods have been developed to expedite the diagnosis of TB, delays in diagnosis remain a major problem in the clinical practice. Because of the slow growth rate of the causative agent Mycobacterium tuberculosis , isolation, identification, and drug susceptibility testing of this organism and other clinically important mycobacteria can take several weeks or longer. During the past several years, many methods have been developed for direct detection, species identification, and drug susceptibility testing of TB. A good understanding of the effectiveness and practical limitations of these methods is important to improve diagnosis. This review summarizes the currently-used advances in nonmolecular and molecular diagnostics.

Pulmonary Tuberculosis Diagnosis: Where We Are?

Leylabadlo, Hamed Ebrahimzadeh,Kafil, Hossein Samadi,Yousefi, Mehdi,Aghazadeh, Mohammad,Asgharzadeh, Mohammad The Korean Academy of Tuberculosis and Respiratory 2016 Tuberculosis and Respiratory Diseases Vol.79 No.3

In recent years, in spite of medical advancement, tuberculosis (TB) remains a worldwide health problem. Although many laboratory methods have been developed to expedite the diagnosis of TB, delays in diagnosis remain a major problem in the clinical practice. Because of the slow growth rate of the causative agent Mycobacterium tuberculosis, isolation, identification, and drug susceptibility testing of this organism and other clinically important mycobacteria can take several weeks or longer. During the past several years, many methods have been developed for direct detection, species identification, and drug susceptibility testing of TB. A good understanding of the effectiveness and practical limitations of these methods is important to improve diagnosis. This review summarizes the currently-used advances in non-molecular and molecular diagnostics.

Macular Thickness in Moderate to Severe Amblyopia

Zhale Rajavi,Hamideh Sabbaghi,Narges Behradfar,Mehdi Yaseri,Mohammad Aghazadeh Amiri,Mohammad Faghihi 대한안과학회 2018 Korean Journal of Ophthalmology Vol.32 No.4

Purpose: To compare the macular retinal thickness of moderately to severely amblyopic eyes with non-amblyopic eyes as controls. Methods: This case control study was conducted on 56 children aged 4 to 10 years old (64.3% female subjects). Twenty-eight children had unilateral amblyopia (28 amblyopic eyes as cases and 28 normal fellow eyes as internal controls) and 28 children had normal visual acuity in both eyes and were considered as external controls (n = 56 eyes). Among our cases, 14 had strabismic amblyopia and 14 had anisometropic amblyopia. Macular retinal thickness was measured using optical coherence tomography at the center and in 1-, 3-, and 6-mm rings. Results: Best-corrected visual acuity of the amblyopic eyes was less than that of the internal and external controls, and the best-corrected visual acuity of their fellow eyes was also less than that of the external controls. Thickness of the central macula and a 1-mm ring area in the amblyopic eyes was higher than that of both internal and external controls. Difference of central macular thickness ≥20 μm between two eyes of the amblyopic children was significantly more than non-amblyopic subjects. Conclusions: Based on the results of this study, the macular retinal thickness was significantly higher in moderate to severe amblyopic eyes compared to their fellow eyes and external controls. This might be due to macular developmental disorders in amblyopic eyes. Therefore, optical coherence tomography imaging is recommended if subtle macular abnormalities are suspected in moderate to severe amblyopic eyes.