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.

Modelling of graded rectangular micro-plates with variable length scale parameters

Aghazadeh, Reza,Dag, Serkan,Cigeroglu, Ender Techno-Press 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.65 No.5

This article presents strain gradient elasticity-based procedures for static bending, free vibration and buckling analyses of functionally graded rectangular micro-plates. The developed method allows consideration of smooth spatial variations of length scale parameters of strain gradient elasticity. Governing partial differential equations and boundary conditions are derived by following the variational approach and applying Hamilton's principle. Displacement field is expressed in a unified way to produce numerical results in accordance with Kirchhoff, Mindlin, and third order shear deformation theories. All material properties, including the length scale parameters, are assumed to be functions of the plate thickness coordinate in the derivations. Developed equations are solved numerically by means of differential quadrature method. Proposed procedures are verified through comparisons made to the results available in the literature for certain limiting cases. Further numerical results are provided to illustrate the effects of material and geometric parameters on bending, free vibrations, and buckling. The results generated by Kirchhoff and third order shear deformation theories are in very good agreement, whereas Mindlin plate theory slightly overestimates static deflection and underestimates natural frequency. A rise in the length scale parameter ratio, which identifies the degree of spatial variations, leads to a drop in dimensionless maximum deflection, and increases in dimensionless vibration frequency and buckling load. Size effect is shown to play a more significant role as the plate thickness becomes smaller compared to the length scale parameter. Numerical results indicate that consideration of length scale parameter variation is required for accurate modelling of graded rectangular micro-plates.

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.

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.

Modelling of graded rectangular micro-plates with variable length scale parameters

Reza Aghazadeh,Serkan Dag,Ender Cigeroglu 국제구조공학회 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.65 No.5

This article presents strain gradient elasticity-based procedures for static bending, free vibration and buckling analyses of functionally graded rectangular micro-plates. The developed method allows consideration of smooth spatial variations of length scale parameters of strain gradient elasticity. Governing partial differential equations and boundary conditions are derived by following the variational approach and applying Hamilton’s principle. Displacement field is expressed in a unified way to produce numerical results in accordance with Kirchhoff, Mindlin, and third order shear deformation theories. All material properties, including the length scale parameters, are assumed to be functions of the plate thickness coordinate in the derivations. Developed equations are solved numerically by means of differential quadrature method. Proposed procedures are verified through comparisons made to the results available in the literature for certain limiting cases. Further numerical results are provided to illustrate the effects of material and geometric parameters on bending, free vibrations, and buckling. The results generated by Kirchhoff and third order shear deformation theories are in very good agreement, whereas Mindlin plate theory slightly overestimates static deflection and underestimates natural frequency. A rise in the length scale parameter ratio, which identifies the degree of spatial variations, leads to a drop in dimensionless maximum deflection, and increases in dimensionless vibration frequency and buckling load. Size effect is shown to play a more significant role as the plate thickness becomes smaller compared to the length scale parameter. Numerical results indicate that consideration of length scale parameter variation is required for accurate modelling of graded rectangular micro-plates.

Effects of Atorvastatin in Patients with Acute Spinal Cord Injury

Javad Aghazadeh,Parviz Samadi Motlagh,Firooz Salehpour,Ali Meshkini,Majid Fatehi,Farhad Mirzaei,Seyed Ahmad Naseri Alavi 대한척추외과학회 2017 Asian Spine Journal Vol.11 No.6

Study Design: Clinical trial study. Purpose: The aim of this study was to evaluate the effect of atorvastatin on sensory and motor function in patients with acute spinal cord injury. Overview of Literature: The prevalence and incidence of traumatic spinal cord injury are increasing. Statins are well established for use in hypercholesterolemia as well as during anti-inflammatory events. Methods: This clinical trial study included 60 patients with acute spinal cord injury. These were randomly divided into two groups: the case group which received atorvastatin and also underwent surgical therapy and the control group which only underwent surgical therapy. Results: The severity of spinal cord lesions was evaluated based on the Frankel grade at three periods; this showed no significant difference between the two groups. Comparisons of the levels of pain between the groups based on a Visual Analog Scale system showed no significant difference at the three periods. Conclusions: We observed no improvement at the 3- and 6-month follow-up in patients who were administered atorvastatin. However, a comparison of the two groups based on pain severity demonstrated a significant difference, suggesting that atorvastatin had a positive effect on patients with spinal cord injury.

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.

Non-invasive Estimation of Intracranial Pressure in Traumatic Brain Injury (TBI) Using Fully-anisotropic Morlet Wavelet Transform and Support Vector Regression

Babak Seyed Aghazadeh,Sardar Ansari,Ramana Pidaparti,Kayvan Najarian 대한의용생체공학회 2013 Biomedical Engineering Letters (BMEL) Vol.3 No.3

Purpose This paper aims to estimate the intracranial pressure (ICP) in patients with traumatic brain injuries (TBI) noninvasively using directional features obtained from the texture of brain CT image and support vector regression (SVR)method. Methods A fully anisotropic Morlet wavelet transform is performed on brain CT images and optimal feature vectors have been extracted to classify the images into two groups of mild and severe TBI. Genetic algorithms with the fitness functions of support vector machines (SVM) classification accuracy rates have been used to find the optimal feature vector. Finally, SVR is implemented to estimate the ICP of patients with TBI. The results are compared to the ones obtained using Dual Tree complex wavelet transform based directional features. Results Features obtained from anisotropic continuous complex wavelet transform are shown to be effective in separating data from two classes of mild and severe TBI. The highest classification accuracy rate of 94.43 percent is achieved. Also, using SVR, the ICP estimation results demonstrate that the proposed algorithm yields excellent performance with a mean absolute error of 4.25 mmHg compared to Dual Tree complex wavelet transform features with the mean absolute error of 5.48 mmHg. Conclusions The severity of TBI is assessed non-invasively using brain CT images, and the directional textural features of brain tissue. The proposed algorithm using anisotropic Morlet wavelet features, GA-SVM based feature selection and SVR methods achieves an excellent performance in ICP estimation for TBI severity assessment.

Effects of Teucrium polium on Insulin Resistance in Nonalcoholic Steatohepatitis

Narges Nosrati,Safiyeh Aghazadeh,Razieh Yazdanparast 사단법인약침학회 2010 Journal of Acupuncture & Meridian Studies Vol.3 No.2

Nonalcoholic fatty liver disease, the most common chronic liver disorder, is frequently associated with the clinical features of metabolic syndrome such as insulin resistance. We aimed to determine the effect of the crude and the ethyl acetate extracts of Teucrium polium on insulin resistance in rats with nonalcoholic steatohepatitis. Rats were divided into four groups. Group A was fed a normal diet for 11weeks. Nonalcoholic steatohepatitis was induced in the remaining groups using a methionine/choline deficient (MCD) diet for 8 weeks. After nonalcoholic steatohepatitis development, group B continued with receiving the MCD diet alone; group C rats were given the MCD diet along with crude extract of T. polium (equivalent to 1 g leaves powder/kg body weight/day); group D rats were given the ethyl acetate fraction of T. polium by intragastric administration for 3 weeks. MCD diet led to grade 1 liver steatosis. In group C and D, these factors abated to grade 0 in 80% of the rats. In the groups receiving the extract, lipoprotein profiles were significantly improved relative to those not receiving the extract. Also, a dramatic reduction was observed in sera alkaline phosphatase, aspartate aminotransferase and alanine aminotransferase activities. In addition, in groups C and D, an increase in the activities of liver superoxide dismutase, glutathione peroxidase and glutathione reductase enzymes were also associated with a decrease in the malondialdehyde level relative to group B. Moreover, both extracts significantly decreased plasma glucose and insulin levels along with insulin resistance. In conclusion, both extracts of T. polium could reverse the adverse effects of an MCD diet.

Effects of adding dexmedetomidine to local infiltration of bupivacaine on postoperative pain in pediatric herniorrhaphy: a randomized clinical trial

Azemati Simin,Pourali Anahita,Aghazadeh Sedigheh 대한마취통증의학회 2020 Korean Journal of Anesthesiology Vol.73 No.3

Background: Postoperative pain is a major problem, especially in children, as their tolerance level is lower and several drugs are contraindicated in childhood. This study aimed to compare the effect of dexmedetomidine added to local infiltration of bupivacaine for postoperative pain relief in children undergoing inguinal herniorrhaphy. Methods: This double-blind, randomized clinical trial included 60 children aged 6–72 months undergoing unilateral herniorrhaphy at selected hospitals in Shiraz, Iran, randomly allocated into two groups, 30 in each group. One group received 1 μg/kg dexmedetomidine plus local infiltration of 0.2 ml/kg bupivacaine 0.5% at the incision site before surgery (BD), and the other group received bupivacaine and normal saline (BO). Analgesic requirements, emergence time, and nausea/vomiting, postoperative pain and sedation scores were assessed for 4 h after the operation. Heart rate (HR), systolic blood pressure (SBP), and oxygen saturation (SaO2) were recorded at baseline, and at 10 and 20 min after injection. Results: Eighty percent were boy in each group; mean age was 22.75 ± 18.63 months. SaO2 and SBP were not different between the groups, while HR was significantly lower in the Group BD at 10 and 20 min after injection (P < 0.05). Group BD had a lower pain score at 1 and 2 h after the operation, a higher sedation score at the first three time intervals, and longer emergence time than Group BO (all P < 0.001). Group BD had a lower pain score at 1 and 2 h after the operation (P < 0.001, P < 0.047 respectively). Conclusions: Addition of dexmedetomidine to local infiltration of bupivacaine in children undergoing herniorrhaphy significantly reduced postoperative pain and increased sedation.