Determining the Etiology of Internuclear Ophthalmoplegia in a Patient with a Cardiac Pacemaker and Complex Neurological Presentation

Bardia Nourbakhsh,Christian Cordano,William Renthal 대한신경과학회 2018 Journal of Clinical Neurology Vol.14 No.4

Biomechanical Comparison of Fixed- versus Variable-Angle Locking Screws for Distal Humerus Comminuted Fractures

Ali Nourbakhsh,Adam G. Hirschfeld,Sravan Dhulipala,William Hutton,Timothy Ganey,Luis Lozada,Daniel Schlatterer,Gary Mark Lourie 대한정형외과학회 2019 Clinics in Orthopedic Surgery Vol.11 No.3

Background: To compare the stability of fixed- versus variable-angle locking constructs for the comminuted distal humerus fracture (AO/OTA 13-A3). Methods: Eight pairs of complete humeri harvested from eight fresh frozen cadavers were used for the study. We fixed the intact humeri using 2.7-mm/3.5-mm locking VA-LCP stainless steel distal humerus posterolateral (nine-hole) and medial (seven-hole) plates. An oscillating saw was used to cut a 1-cm gap above the olecranon fossa. The specimens were loaded in axial mode with the rate of 1 mm per 10 seconds to failure, and stress-strain curves were compared in each pair. The mode of failure was recorded as well as the load needed for 2- and 4-mm displacement at the lateral end of the gap. Results: The stiffness of the constructs, based on the slope of the stress-strain curve, did not show any difference between the fixed- versus variable-angle constructs. Likewise, there was no difference between the force needed for 2- or 4-mm displacement at the lateral gap between the fixed- and variable-angle constructs. The mode of failure was bending of both plates in all specimens and screw pull-out in four specimen pairs in addition to the plate bending. Conclusions: Our results did not show any difference in the biomechanical stability of the fixed- versus variable-angle constructs. There was not any screw breakage or failure of the plate-screw interface.

Mixture rule for studding the environmental pollution reduction in concrete structures containing nanoparticles

Tabatabaei, Javad,Nourbakhsh, Seyed Hesam,Siahkar, Mahdi Techno-Press 2020 Coupled systems mechanics Vol.9 No.3

Nanotechnology is an upcoming technology that can provide solution for combating pollution by controlling shape and size of materials at the nanoscale. This review provides comprehensive information regarding the role of nanotechnology in pollution control at concrete structures. Titanium dioxide (TiO2) nanoparticles are a good item for concrete structures for diminishing the air polluting affect by gasses of exhaust. In this article, the mixture rule is presented for the effect of nanoparticles in environmental pollution reduction in concrete structures. The compressive strength, elastic modulus and reduction of steel bars in the concrete structures are studied. The Results show that TiO2 nanoparticles have significant effect on the reduction of environmental pollution and increase of stiffness in the concrete structures. In addition, the nanoparticles can reduce the use of steel bars in the concrete structure.

GIS-based evaluation of geomorphic response to tectonic activity in Makran Mountain Range, SE of Iran

Abdolreza Partabian,Ahmad Nourbakhsh,Sohelia Ameri 한국지질과학협의회 2016 Geosciences Journal Vol.20 No.6

This paper investigates the impact of active tectonics on the geomorphic processes and landscape evolution of Makran Mountain range at southeastern of Iran using spatial analysis of geomorphic indices. We documented how topography and morphology are influenced by active tectonic deformation. Quantitative analysis of the geomorphological response to active tectonics within the study area have been done using drainage basin asymmetry factor (Af), drainage basin shape index (Bs), drainage density index (Dd), hypsometric integral (Hi), mean axial slope of the channel (MASC), topographic roughness (STD), mountain-front sinuosity (Smf) and valley floor width-valley height ratio (Vf). The obtained results from these indices were combined to yield an index of active tectonics (Iat). The indicative values of this index are consistent with the landforms and geology of the study area. The morphometric data (quantitative analysis of geomorphic indices) provides evidence of relative variation in the tectonic activity of the study area and related landforms. The utilization of geomorphic parameters exhibits decrease in the geomorphic response of the landforms from north to south. Also, the Ghasr-e-Ghand fault, based on the front-based indices has an important role in uplift of the middle part of the study area. Based upon the results of this study we suggest a southward tectonic vergence for the Makran Mountain Range.

Fabrication and Characterization of Electrospun Scaffold Based on Polycaprolactone-Aloe vera and Polyvinyl Alcohol for Skin Tissue Engineering

Marjan Shabannejad,Mohammad Sadegh Nourbakhsh,Amir Salati,Zohreh Bahrami 한국섬유공학회 2020 Fibers and polymers Vol.21 No.8

In the present work, the biodegradable nanofibrous scaffolds containing poly(caprolactone) (PCL), poly(vinylalcohol) (PVA) and aloe vera (AV), through two nozzles electrospinning method, were prepared and characterized byscanning electron microscopy, Fourier transform infrared spectroscopy, contact angle measurement and mechanical analysis. The biocompatibility and cell growth were evaluated using MTT (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazoliumbromide) assay. Adding poly(vinyl alcohol) (PVA) and poly(caprolactone) (PCL) boosted the electrospinability of aloe vera(AV) solution and mechanical features of the scaffolds. According to the Scanning electron microscopy (SEM) results,uniform PVA/AV-PCL nanofibers were fabricated with the average diameter about 119±11.78 nm. Fourier-transform infraredspectroscopy) FTIR (confirmed the presence of functional groups of scaffolds. The results of the contact angle showed thatby adding aloe vera, the hydrophilicity increased. The results showed that the tensile strength of samples with 6 mg/ml AV,reached to 2.02 MPa. MTT results showed that all samples had a cell viability of over 80 %. It can be concluded thatnanofibrous scaffolds with concentration of 6 mg/ml, distance between syringe tip/collector of 15 cm, feed rate of 3 ml/h andapplied voltage of 12 kV, have appropriate properties for skin tissue engineering by stimulating the fibroblast cells andtherefore accelerating the regeneration processes of damaged skin.

Encapsulation of Frankincense Essential Oil by Microfluidic and Bulk Approaches: A Comparative Study

Pouria Taherian,Mohammad Sadegh Nourbakhsh,Ali Abouei Mehrizi,Mohadeseh Hashemi 한국섬유공학회 2022 Fibers and polymers Vol.23 No.10

Herbs and hand-made herbal remedies have been long used for disease control, treatment, and healthimprovement. Evidence suggests that a single herb's compounds can have synergistic functions with probably no adverseeffect. Unfortunately, the traditional administration of essential oil (EO) does not follow a regulatory dose regimen, causingreduced bioavailability due to EO evaporation or denaturation in harsh biological environments. Hence, encapsulation canhelp enhance EO stability and dose dependence. Here, chitosan nanoparticles (ChNPs) were used to encapsulate frankincenseessential oil (FEO) to preserve its remarkable therapeutic effects. Also, traditional bulk preparation methods were comparedwith microfluidic with central aqueous stream configuration (CAS). The results indicated the higher quality of microfluidicbasednanoparticles with uniform, spherical, and separated morphologies. The size of bulk and microfluidic nanoparticlesranged from 86 to 118 nm, the surface charge varied from 12.5 to 19.5 for different amounts of FEO, and the as-preparedcolloid remained stable for three days. Narrow size distribution (PDI0.28) and high encapsulation efficiency (EE99 %)were achieved using the microfluidic process compared to the bulk method (PDI=0.74, EE90 %). The microfluidicnanoparticle also indicated a burst release rate greater than the bulk method (30 %). It was concluded that the highperformancemicrofluidic approach provided higher quality and more control over nanoparticle properties.

Electrospun Skin Tissue Engineering Scaffolds Based on Polycaprolactone/Hyaluronic Acid/L-ascorbic Acid

Mahsa Janmohammadi,Mohammad Sadegh Nourbakhsh,Shahin Bonakdar 한국섬유공학회 2021 Fibers and polymers Vol.22 No.1

Skin tissue engineering is an evolving method to reconstruct skin damages caused by disease, burn or trauma. Inskin tissue engineering, scaffolds should prepare three-dimensional structure for skin cells. Electrospinning technique hasbeen widely applied for producing nano/micro-scale fiber scaffolds in tissue engineering. In this study, electrospun scaffoldsbased on polycaprolactone (PCL) and hyaluronic acid (HA) containing L-ascorbic acid (AA) were fabricated. Morphology,contact angle, functional groups, biodegradability and drug release of the scaffolds were evaluated. L929 fibroblast cellsseeded on nanofibrous scaffolds and cell attachment and viability were evaluated as well. According to the results, the fibersdiameter were less than 180 nm and by adding hyaluronic acid, the hydrophilicity of scaffolds increased and degradation ratewas adjusted. The encapsulation efficiency and successful release of ascorbic acid in nanofibrous scaffolds weredemonstrated. According to the results, the cell growth, proliferation and adhesion of L929 fibroblast cells on the PCL/HA/AA scaffolds were enhanced in comparison with the PCL scaffold. Moreover, PCL/HA (80:20) containing 40 mg of AAnanofibrous scaffold could be potentially applied for skin tissue engineering.

Isolation and Characterization of Pb-Solubilizing Bacteria and Their Effects on Pb Uptake by Brassica juncea: Implications for Microbe- Assisted Phytoremediation

( Zahra Yahaghi ),( Mehran Shirvani ),( Farshid Nourbakhsh ),( Teodoro Coba De La Pena ),( Jose J. Pueyo ),( Majid Talebi ) 한국미생물생명공학회(구 한국산업미생물학회) 2018 Journal of microbiology and biotechnology Vol.28 No.7

The aim of this study was to isolate and characterize lead (Pb)-solubilizing bacteria from heavy metal-contaminated mine soils and to evaluate their inoculation effects on the growth and Pb absorption of Brassica juncea. The isolates were also evaluated for their plant growthpromoting characteristics as well as heavy metal and salt tolerance. A total of 171 Pb-tolerant isolates were identified, of which only 15 bacterial strains were able to produce clear haloes in solid medium containing PbO or PbCO₃, indicating Pb solubilization. All of these 15 strains were also able to dissolve the Pb minerals in a liquid medium, which was accompanied by significant decreases in pH values of the medium. Based on 16S rRNA gene sequence analysis, the Pb-solubilizing strains belonged to genera Bacillus, Paenibacillus, Brevibacterium, and Staphylococcus. A majority of the Pb-solubilizing strains were able to produce indole acetic acid and siderophores to different extents. Two of the Pb-solubilizing isolates were able to solubilize inorganic phosphate as well. Some of the strains displayed tolerance to different heavy metals and to salt stress and were able to grow in a wide pH range. Inoculation with two selected Pb-solubilizing and plant growth-promoting strains, (i.e., Brevibacterium frigoritolerans YSP40 and Bacillus paralicheniformis YSP151) and their consortium enhanced the growth and Pb uptake of B. juncea plants grown in a metal-contaminated soil. The bacterial strains isolated in this study are promising candidates to develop novel microbe-assisted phytoremediation strategies for metal-contaminated soils.

Estimation of flow curve and friction coefficient by means of a one-step ring test using a neural network coupled with FE simulations

Faramarz Fereshteh-Saniee,S. Hassan Nourbakhsh,S. Mahmoud Pezeshki 대한기계학회 2012 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.26 No.1

This paper is concerned with application of artificial neural network (ANN) to the ring compression test for simultaneous determination of the flow curve of the material and the friction factor. The developed ANN model was trained using data from 700 finiteelement (FE) simulations of the ring test. The load curve of this test and the final internal diameter of the sample are the inputs for this ANN model and the outputs are the strength coefficient, strain hardening exponent and the friction factor. It was found that the outputs of the developed ANN model were in good agreement with the experimental results.

Analytical and Numerical Study of Fluid Flow in Propeller-type Current-meters

Mohammad Hossein Khozaei,Seyed Ahmad Nourbakhsh 한국유체기계학회 2020 International journal of fluid machinery and syste Vol.13 No.2

Current-meters are well-known water flowrate measuring instruments in industry, and for many years, they have been used to measure flow velocity in open channels and closed conduits. Despite the extent of their application, there is not much information on basic equations of propeller-type current-meters. This paper is dedicated to present a novel design method for propeller-type current-meters. First of all, the basics of current-meters are theoretically investigated through momentum and airfoil theory approaches. Then, the essential design parameters are discussed to shape the design method. The current-meters are divided into three groups by considering their axial pitch values: low-, medium-, and high-pitch; and for each group, the design procedure is demonstrated thoroughly. In addition, the influence of axial pitch value is numerically studied on performance of current-meters via an experimentally validated CFD model. It is shown that low-pitch current-meters are more sensitive to velocity changes, and high pith meters are more reliable in different flow conditions.