Comparison of an Adaptive Neuro-fuzzy Inference System and an Artificial Neural Network in the Cross-talk Correction of Simultaneous 99mTc / 201Tl SPECT Imaging Using a GATE Monte-Carlo Simulation

Saeed Heidary,Saeed Setayeshi,Mohammad Ghannadi-Maragheh 한국물리학회 2014 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.65 No.5

The aim of this study is to compare the adaptive neuro-fuzzy inference system (ANFIS) andthe artificial neural network (ANN) to estimate the cross-talk contamination of 99mTc / 201Tlimage acquisition in the 201Tl energy window (77 ± 15% keV). GATE (Geant4 Application inEmission and Tomography) is employed due to its ability to simulate multiple radioactive sourcesconcurrently. Two kinds of phantoms, including two digital and one physical phantom, are used. Inthe real and the simulation studies, data acquisition is carried out using eight energy windows. TheANN and the ANFIS are prepared in MATLAB, and the GATE results are used as a training dataset. Three indications are evaluated and compared. The ANFIS method yields better outcomes fortwo indications (Spearman’s rank correlation coefficient and contrast) and the two phantom resultsin each category. The maximum image biasing, which is the third indication, is found to be 6%more than that for the ANN.

Capability of Tuff and Tuff Derived Soils in Carbon Stabilization

Ahmad Heidari,Saeed Hamzehee 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

Free vibration of sandwich micro-beam with porous foam core, GPL layers and piezo-magneto-electric facesheets via NSGT

Mehdi Mohammadimehr,Saeed Firouzeh,Mahsa Pahlavanzadeh,Yaser Heidari,Mohsen Irani-Rahaghi 사단법인 한국계산역학회 2020 Computers and Concrete, An International Journal Vol.26 No.1

The aim of this research is to investigate free vibration of a novel five layer Timoshenko microbeam which consists of a transversely flexible porous core made of Al-foam, two graphen platelets (GPL) nanocomposite reinforced layers to enhance the mechanical behavior of the structure as well as two piezo-magneto-electric face sheets layers. This microbeam is subjected to a thermal load and resting on Pasternak’s foundation. To accomplish the analysis, constitutive equations of each layer are derived by means of nonlocal strain gradient theory (NSGT) to capture size dependent effects. Then, the Hamilton’s principle is employed to obtain the equations of motion for five layer Timoshenko microbeam. They are subsequently solved analytically by applying Navier’s method so that discretized governing equations are determined in form of dynamic matrix giving the possibility to gain the natural frequencies of the Timoshenko microbeam. Eventually, after a validation study, the numerical results are presented to study and discuss the influences of various parameters such as nonlocal parameter, strain gradient parameter, aspect ratio, porosity, various volume fraction and distributions of graphene platelets, temperature change and elastic foundation coefficients on natural frequencies of the sandwich microbeam.

Cross-Linked Collagen Scaffold from Fish Skin as an Ideal Biopolymer for Tissue Engineering

Esmaeil Biazar,Mahshad Kamalvand,Saeed Heidari Keshel,Bahareh Pourjabbar,Mustafa Rezaei-Tavirani 한국재료학회 2022 한국재료학회지 Vol.32 No.4

Collagen is one of the most widely used biological materials in medical design. Collagen extracted from marine organisms can be a good biomaterial for tissue engineering applications due to its suitable properties. In this study, collagen is extracted from fish skin of Ctenopharyngodon Idella; then, the freeze drying method is used to design a porous scaffold. The scaffolds are modified with the chemical crosslinker N-(3-Dimethylaminopropyl)-N'-ethyl carbodiimide hydrochloride (EDC) to improve some of the overall properties. The extracted collagen samples are evaluated by various analyzes including cytotoxicity test, SDS-PAGE, FTIR, DSC, SEM, biodegradability and cell culture. The results of the SDS-PAGE study demonstrate well the protein patterns of the extracted collagen. The results show that cross-linking of collagen scaffold increases denaturation temperature and degradation time. The results of cytotoxicity show that the modified scaffolds have no toxicity. The cell adhesion study also shows that epithelial cells adhere well to the scaffold. Therefore, this method of chemical modification of collagen scaffold can improve the physical and biological properties. Overall, the modified collagen scaffold can be a promising candidate for tissue engineering applications.

Effect of PEG Molecular Weight and Volume Ratio of Chitosan/PEG and Silk Fibroin on Physicomechanical Properties of Chitosan/PEG-SF Scaffold as a Bio-mimetic Substrate in Skin-tissue Engineering Applications

Azadeh Izadyari Aghmiuni,Saeed Heidari Keshel,Mostafa Rezaei-Tavirani,Farshid Sefat,Arash Khojasteh,Masoud Soleimani,Farzad Pakdel 한국섬유공학회 2022 Fibers and polymers Vol.23 No.12

Tissue engineering provides new approaches to improve skin lesions. However, cell differentiation onto theengineered substrate with the skin-like pattern is the main challenge. Here we have tried to fabricate such the substrate viastudying the change in polymers ratios and molecular weight, and grafting scaffold with silk fibroin (SF) biomaterial. To thisend, chitosan and PEG were mixed at the volume ratios of 25:75, 50:50, and 65:35, and samples were lyophilized by thefreeze-drying method. Based on the result, the ratio of 65:35 indicated better physicomechanical properties than two otherscaffolds. Afterward, Chi/PEG scaffolds were prepared via mixing chitosan/PEG with (65:35) and PEG molecular weights of2000, 4000, 6000, 10000 Da. It was found that the increase of PEG molecular weight (>4000) was led to the reduction intensile strength and elongation of the scaffold network. Hence, PEG4000 was selected as the optimum molecular weight todesign SF-grafted Chi/PEG scaffold. Therefore, Chi/PEG4000-SF scaffold was designed to evaluate the volume ratio of SF(1 %, 3 %, 5 %) and compare data with the decellularized dermis. The results showed Chi/PEG4000-SF(3%) scaffold not onlywas led to the same elongation as Chi/PEG-SF(5%) scaffold but also created the dermis-like modulus. Moreover, Chi/PEGSF(3%) provided higher expression level of keratinocytes (bio-mimetic pattern) than decellularized dermis due to betterphysicomechanical properties. Hence, it seems that engineered scaffolds can be a more suitable option than native tissue (dueto removal of limitations such as donor sites and immunogenicity, and their mechanical properties). This study can providenovel insight into the better design of skin-engineered scaffolds.

Synthesis, characterization, and toxicity of multi-walled carbon nanotubes functionalized with 4-hydroxyquinazoline

Hasan Tahermansouri,Atieh Mirosanloo,Saeed Heidari Keshel,Mossa Gardaneh 한국탄소학회 2016 Carbon Letters Vol.17 No.-

The attachment of 2-aminobenzamide to carboxylated multi-wall carbon nanotubes (MWCNTs)- COOH was achieved through the formation of amide bonds. Then, the functionalized MWCNTs, MWCNT-amide, were treated by phosphoryl chloride to produce MWCNT-quin. The products were characterized by Fourier transform infrared spectroscopy, Raman spectroscopy, scanning electron microscopy, thermogravimetric analysis, derivative thermogravimetric, steady-state fluorescence spectroscopy, and solubility testing. MWCNT-quin showed photo-electronic properties, which is due to the attachment of the 4-hydroxyquinazoline groups to them as proved by steady-state fluorescence spectroscopy. This suggests intramolecular interactions between the tubes and the attached 4-hydroxyquinazoline. The toxicity of the samples was evaluated in human embryonic kidney HEK293 and human breast cancer SKBR3 cell lines, and the viable cell numbers were measured by 3-(4,5-dimethyl- 2-thiazolyl)-2,5-diphenyltetrazolium bromide (MTT) after the cells were cultured for 24 h. Cellular investigations showed that the modified MWCNTs, particularly MWCNT- quin, have considerably significant toxic impact on SKBR3 as compared to HEK293 at the concentration of 5 μg/mL.

Design of Novel 3D-Scaffold as a Potential Material to Induct Epidermal-Dermal Keratinocytes of Human-Adipose-Derived Stem Cells and Promote Fibroblast Cells Proliferation for Skin Regeneration

Azadeh Izadyari Aghmiuni,Mazyar Sharifzadeh Baei,Saeed Heidari Keshel,Azim Akbarzadeh Khiyavi 한국섬유공학회 2020 Fibers and polymers Vol.21 No.1

Dermal lesions and chronic wounds associated with burns or some diseases like diabetes are the more importantpublic health concerns which can affect the quality of life. Currently, tissue engineering is considered as the most effectivetherapeutic method although the design of polymeric substrates for epidermal-dermal differentiation and wound healing(scar-free) is the main challenge. For this purpose, we designed a hybrid three-dimensional scaffold (CPCP) based oncollagen/chitosan modified by PEG/PCL composite that can imitate differentiation pattern of both epidermis/dermis cells, viamimicking the structure and function of human skin. The physicochemical, mechanical and biological properties of designedscaffolds were evaluated to study their function for skin tissue engineering applications. Comparison of FTIR analysisshowed a chemical similarity between CPCP and decellularized dermal matrix (DDM). Our results showed that combinationof two natural/two synthetic polymers led to the formation of stronger 3D-network together with higher modulus (~18), waterabsorption (4-fold), porosity (~92) and consequently lower pores size (~54 μm), compared to natural, synthetic and natural/synthetic copolymer-based scaffolds. The observation of human skin fibroblast cells proliferation and morphology showedthat CPCP was more beneficial to cell adhesion, proliferation, and extension than that of other designed scaffolds due to itshydrophilicity and higher wettability (WCA=60 o). According to the results of RT-PCR, the more expression of epidermaldermalkeratinocytes induced by human-adipose-derived stem cells was observed on the CPCP along with a pattern similar toskin. The results demonstrate CPCP can act as a super-absorbent substrate/dressing for continuous absorption of woundexudates. Furthermore, it can potentially be effective for re-epithelialization of skin together with its derivative (hair follicles,sebaceous/sweat glands). This study indicates new insights into the design of skin- engineered scaffolds.

The Effect of Transcutaneous Electrical Nerve Stimulation of Sympathetic Ganglions and Acupuncture Points on Distal Blood Flow

Fahimeh Kamali,Hossein Mirkhani,Ahmadreza Nematollahi,Saeed Heidari,Elahesadat Moosavi,Marzieh Mohamadi 사단법인약침학회 2017 Journal of Acupuncture & Meridian Studies Vol.10 No.2

Transcutaneous electrical nerve stimulation (TENS) is awidely-practiced method to increase blood flow in clinical practice. The best location for stimulation to achieve optimal blood flow has not yet been determined. We compared the effect of TENS application at sympathetic ganglions and acupuncture points on blood flow in the foot of healthy individuals. Seventy-five healthy individuals were randomly assigned to three groups. The first group received cutaneous electrical stimulation at the thoracolumbar sympathetic ganglions. Thesecond group received stimulation at acupuncture points. Thethird group received stimulation in the mid-calf area as a control group. Blood flowwas recorded at time zero as baseline and every 3 minutes after baseline during stimulation, with a laser Doppler flow-meter. Individuals who received sympathetic ganglion stimulation showed significantly greater blood flow than those receiving acupuncture point stimulation or those in the control group (p < 0.001). Data analysis revealed that blood flow at different times during stimulation increased significantly from time zero in each group. Therefore, the application of lowfrequency TENS at the thoracolumbar sympathetic ganglions was more effective in increasing peripheral blood circulation than stimulation at acupuncture points.