Theoretical study of diffusional release of a dispersed solute from a hollow cylindrical polymeric matrix

, Article Scientia Iranica ; Volume 28, Issue 3 , 2021 , Pages 1428-1435 ; 10263098 (ISSN) Jooybar, E ; Tajsoleiman, T ; Abdekhodaie, M. J ; Sharif University of Technology

Sharif University of Technology 2021

Abstract

The present study proposes an exact solution for the release kinetic of a solute from inside a hollow cylindrical polymeric matrix into an infinite medium when the initial concentration of the solute (A) is greater than the solubility limit (Cs). A combination of analytical and numerical methods was used to calculate the solute concentration profile and the release rate. The model was developed for two different conditions including: (1) The release medium was flowing through the hollow cylinder in which the boundary layer may be neglected, and (2) The release medium inside the hollow cylinder was stagnant where the boundary layer needed to be considered. The results indicated that the...

Computational modeling of drug distribution in the posterior segment of the eye: Effects of device variables and positions

, Article Mathematical Biosciences ; Vol. 255, issue. 1 , 2014 , p. 11-20 Jooybar, E ; Abdekhodaie, M. J ; Farhadi F ; Cheng Y. L ; Sharif University of Technology

2014

Abstract

A computational model was developed to simulate drug distribution in the posterior segment of the eye after intravitreal injection and ocular implantation. The effects of important factors in intravitreal injection such as injection time, needle gauge and needle angle on the ocular drug distribution were studied. Also, the influences of the position and the type of implant on the concentration profile in the posterior segment were investigated. Computational Fluid Dynamics (CFD) calculations were conducted to describe the 3D convective-diffusive transport. The geometrical model was constructed based on the human eye dimensions. To simulate intravitreal injection, unlike previous studies...

Developing Polymeric Carriers for Delivery of Platelet Lysate Aiming Tissue Regeneration

, Ph.D. Dissertation Sharif University of Technology Jooybar, Elaheh (Author) ; Abdekhodaie, Mohammad Jafar (Supervisor) ; Mousavi, Abbas (Supervisor)

Abstract

The goal of tissue engineering is the restoration of a tissue function based on combination of cells, scaffolds, and biological signals in an engineered structure. The best way to develop this issue is mimicking the body and host tissues. In the present thesis, it was tried to improve cartilage tissue regeneration from two aspects. In the first part, an injectable hydrogel based on hyaluronic acid (HA) biomaterial was developed which was incorporated with platelet lysate (PL), as an autologous source of growth factors. The human mesenchymal stem cells (hMSCs) were encapsulated in the hydrogel and the effects of PL on the cell attachment, viability and differentiation toward chondrocytes were...

Simulation and Optimization of Drug Delivery Methods to Eye

, M.Sc. Thesis Sharif University of Technology Jooybar, Elaheh (Author) ; Abdekhodaie, Mohammad Jafar (Supervisor) ; Farhadi, Fatollah (Supervisor)

Abstract

In this study a mathematical model for intravitreal injection and depositing controlled release systems in the eye to treat posterior segment deseases is developed. The effects of important parameters that play a critical role in drug distribution are also studied.
Geometrical model is constructed using COMSOL software and governing equations for a 3-D model of drug distribution are solved by finite element method. The geometry is based on the exact dimensions of human eye and retina, choroid and sclera are considered separately. Choroidal losses to the circulatory system and active transport by the retinal pigment epithelium are incorporated as well. Moreover, two types of implant...

Enzymatically crosslinked hyaluronic acid microgels as a vehicle for sustained delivery of cationic proteins

, Article European Polymer Journal ; Volume 115 , 2019 , Pages 234-243 ; 00143057 (ISSN) Jooybar, E ; Abdekhodaie, M. J ; Mousavi, A ; Zoetebier, B ; Dijkstra, P. J ; Sharif University of Technology

Elsevier Ltd 2019

Abstract

In this study, a novel biodegradable hyaluronic acid (HA) based microgel were prepared via enzymatic crosslinking of tyramine conjugated HA (HA-TA) in an inverse microemulsion. HA-TA microdroplets were crosslinked within a few seconds in the presence of horseradish peroxidase (HRP) and hydrogen peroxide (H 2 O 2 ). The high water content of the polymeric network and the inherent negative charge of the HA-TA microgels provided a suitable platform for encapsulation of cationic proteins like lysozyme and TGF-β1 growth factor. The results demonstrated that lysozyme was released, after an initial burst release, in a suitable sustained manner over a period of four weeks. Both diffusion and...

An injectable platelet lysate-hyaluronic acid hydrogel supports cellular activities and induces chondrogenesis of encapsulated mesenchymal stem cells

, Article Acta Biomaterialia ; 2018 ; 17427061 (ISSN) Jooybar, E ; Abdekhodaie, M. J ; Alvi, M ; Mousavi, A ; Karperien, M ; Dijkstra, P. J ; Sharif University of Technology

Acta Materialia Inc 2018

Abstract

Developing scaffolds that can provide cells and biological cues simultaneously in the defect site is of interest in tissue engineering field. In this study, platelet lysate (PL) as an autologous and inexpensive source of growth factors was incorporated into a cell-laden injectable hyaluronic acid-tyramine (HA-TA) hydrogel. Subsequently, the effect of platelet lysate on cell attachment, viability and differentiation of human mesenchymal stem cell (hMSCs) toward chondrocytes was investigated. HA-TA conjugates having a degree of substitution of 20 TA moieties per 100 disaccharide units were prepared and crosslinked in the presence of horseradish peroxidase and low concentrations of hydrogen...

Developing hyaluronic acid microgels for sustained delivery of platelet lysate for tissue engineering applications

, Article International Journal of Biological Macromolecules ; Volume 144 , 2020 , Pages 837-846 Jooybar, E ; Abdekhodaie, M. J ; Karperien, M ; Mousavi, A ; Alvi, M ; Dijkstra, P. J ; Sharif University of Technology

Elsevier B.V 2020

Abstract

Platelet lysate (PL), a blood product that contains high concentrations of growth factors (GFs), can be considered as a cost-effective source of multiple GFs. In this study, hyaluronic acid (HA) based microgels were developed for delivery of PL proteins. Spherical microgel were prepared using a water in oil emulsion method. First, hyaluronic acid was grafted with tyramine groups, after which prepared microdroplets were crosslinked via an enzymatic reaction in the presence of hydrogen peroxide and horseradish peroxidase. Because of electrostatic interactions, these microgels are promising carriers for positively charged proteins entrapment like most of the GFs. When microgels are incubated in...

Dose-dependent effects of nanoscale graphene oxide on reproduction capability of mammals

, Article Carbon ; Volume 95 , December , 2015 , Pages 309-317 ; 00086223 (ISSN) Akhavan, O ; Ghaderi, E ; Hashemi, E ; Akbari, E ; Sharif University of Technology

Elsevier Ltd 2015

Abstract

In vivo dose-dependent effects of nanoscale graphene oxide (NGO) sheets on reproduction capability of Balb/C mice were investigated. Biodistribution study of the NGO sheets (intravenously injected into male mice at dose of ∼2000 μg/mL or 4 mg/kg of body weight) showed a high graphene uptake in testis. Hence, in vivo effects of the NGO sheets on important characteristics of spermatozoa (including their viability, morphology, kinetics, DNA damage and chromosomal aberration) were evaluated. Significant in vivo effects was found at the injected concentrations ≥200 μg/mL after (e.g., ∼45% reduction in sperm viability and motility at 2000 μg/mL). Observation of remarkable DNA fragmentations and...

Accelerated differentiation of neural stem cells into neurons on ginseng-reduced graphene oxide sheets

, Article Carbon ; Volume 66 , January , 2014 , Pages 395-406 Akhavan, O ; Ghaderi, E ; Abouei, E ; Hatamie, S ; Ghasemi, E ; Sharif University of Technology

2014

Abstract

Asian red ginseng was used for green reduction of chemically exfoliated graphene oxide (GO) into reduced graphene oxide (rGO). The reduction level and electrical conductivity of the ginseng-rGO sheets were comparable to those of hydrazine-rGO ones. Reduction by ginseng resulted in repairing the sp 2 graphitic structure of the rGO, while hydrazine-rGO showed more defects and/or smaller aromatic domains. The ginseng-rGO sheets presented a better stability against aggregation than the hydrazine-rGO ones in an aqueous suspension. Whilst the hydrophobic hydrazine-rGO films exhibited no toxicity against human neural stem cells (hNSCs), the hydrophilic GO and ginseng-rGO films (as more...

Contested framings and policy controversies: Analysing biosafety policy-making in Iran

, Article Science and Public Policy ; Volume 40, Issue 5 , 2013 , Pages 616-627 ; 03023427 (ISSN) Kashani, E. S ; Millstone, E ; Sharif University of Technology

2013

Abstract

Vigorous debates have taken place within and between many countries about regulatory policy regimes covering the assessment and approval of genetically modified (GM) crops. In Iran, a very vigorous and hotly contested policy debate concerning legislation covering GM crops occurred between 2004 and 2009, but it was confined within government circles with almost no public discussion. This paper analyses the Iranian policy-making process in the period 2006-9. It explains how and why a stalemate arose in disputes between ministries and departments. The chosen analytical framework draws mainly on the regulation of technological risks and the analysis of public policy-making. It deploys the...

On the possible volumes of μ-way latin trades

, Article Aequationes Mathematicae ; Volume 63, Issue 3 , 2002 , Pages 303-320 ; 00019054 (ISSN) Adams, P ; Billington, E. J ; Bryant, D. E ; Mahmoodian, E. S ; Sharif University of Technology

Birkhauser Verlag Basel 2002

Abstract

A μ-way latin trade of volume s is a set of μ partial latin rectangles (of inconsequential size) containing exactly the same s filled cells, such that if cell (i, j) is filled, it contains a different entry in each of the μ partial latin rectangles, and such that row i in each of the μ partial latin rectangles contains, set-wise, the same symbols and column j, likewise. In this paper we show that all μ-way latin trades with sufficiently large volumes exist, and state some theorems on the non-existence of μ-way latin trades of certain volumes. We also find the set of possible volumes (that is, the volume spectrum) of μ-way latin trades for μ = 4 and 5. (The case μ = 2 was dealt with by Fu,...

The three-way intersection problem for latin squares

, Article Discrete Mathematics ; Volume 243, Issue 1-3 , 2002 , Pages 1-19 ; 0012365X (ISSN) Adams, P ; Billington, E. J ; Bryant, D. E ; Mahmoodian, E. S ; Sharif University of Technology

2002

Abstract

The set of integers k for which there exist three latin squares of order n having precisely k cells identical, with their remaining n2 -k cells different in all three latin squares, denoted by I3[n], is determined here for all orders n. In particular, it is shown that I3[n] = {0,.,n2 -15}U [n2 - 12,n2-9,n2], for n ≫8. ©2002 Eisevier Science B.V. All rights reserved

Integration of spatial fuzzy clustering with level set for segmentation of 2-D angiogram

, Article IECBES 2014, Conference Proceedings - 2014 IEEE Conference on Biomedical Engineering and Sciences: "Miri, Where Engineering in Medicine and Biology and Humanity Meet", 8 December 2014 through 10 December 2014 ; December , 2015 , Pages 309-314 ; 9781479940844 (ISBN) Ghalehnovi, M ; Zahedi, E ; Fatemizadeh, E ; Sharif University of Technology

Institute of Electrical and Electronics Engineers Inc 2015

Abstract

Coronary angiography is a vital instrument to detect the prevailing of vascular diseases, and accurate vascular segmentation acts a crucial role for proper quantitative analysis of the vascular tree morphological features. Level set methods are popular for segmenting the coronary arteries, but their performance is related to suitable start-up and optimum setting of regulating parameters, essentially done manually. This research presents a novel fuzzy level set procedure with the objective of segmentation of the coronary artery tree in 2-D X-ray angiography as automatically. It is clever to clearly develop from the early segmentation with spatial fuzzy grouping. The adjusting parameters of...

Deep relative attributes

, Article 13th Asian Conference on Computer Vision, ACCV 2016, 20 November 2016 through 24 November 2016 ; Volume 10115 LNCS , 2017 , Pages 118-133 ; 03029743 (ISSN); 9783319541921 (ISBN) Souri, Y ; Noury, E ; Adeli, E ; Sharif University of Technology

Springer Verlag 2017

Abstract

Visual attributes are great means of describing images or scenes, in a way both humans and computers understand. In order to establish a correspondence between images and to be able to compare the strength of each property between images, relative attributes were introduced. However, since their introduction, hand-crafted and engineered features were used to learn increasingly complex models for the problem of relative attributes. This limits the applicability of those methods for more realistic cases. We introduce a deep neural network architecture for the task of relative attribute prediction. A convolutional neural network (ConvNet) is adopted to learn the features by including an...

A public code for astrometric microlensing with contour integration

, Article Monthly Notices of the Royal Astronomical Society ; Volume 505, Issue 1 , 2021 , Pages 126-135 ; 00358711 (ISSN) Bozza, V ; Khalouei, E ; Bachelet, E ; Sharif University of Technology

Oxford University Press 2021

Abstract

We present the first public code for the calculation of the astrometric centroid shift occurring during microlensing events. The computation is based on the contour integration scheme and covers single and binary lensing of finite sources with arbitrary limb darkening profiles. This allows for general detailed investigations of the impact of finite source size in astrometric binary microlensing. The new code is embedded in version 3.0 of vbbinarylensing, which offers a powerful computational tool for extensive studies of microlensing data from current surveys and future space missions. © 2021 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society

Toward electrically tunable, lithography-free, ultra-thin color filters covering the whole visible spectrum

, Article Scientific Reports ; Volume 8, Issue 1 , 2018 ; 20452322 (ISSN) Aalizadeh, M ; Serebryannikov, A. E ; Khavasi, A ; Vandenbosch, G. A. E ; Ozbay, E ; Sharif University of Technology

Nature Publishing Group 2018

Abstract

The possibility of real-time tuning of optical devices has attracted a lot of interest over the last decade. At the same time, coming up with simple lithography-free structures has always been a challenge in the design of large-area compatible devices. In this work, we present the concept and the sample design of an electrically tunable, lithography-free, ultra-thin transmission-mode color filter, the spectrum of which continuously covers the whole visible region. A simple Metal-Insulator-Metal (MIM) cavity configuration is used. It is shown that using the electro-optic dielectric material of 4-dimethyl-amino-N-methyl-4-stilbazoliumtosylate (DAST) as the dielectric layer in this...

A novel method for modeling the magnetizing yoke

, Article Electromagnetics ; Volume 30, Issue 3 , 2010 , Pages 297-308 ; 02726343 (ISSN) Ravanbod, H ; Norouzi, E

2010

Abstract

Magnetic flux leakage is the most widely used method for oil and gas pipeline non destructive testing. The saturation level of the sample under test has a significant effect on its efficiency; therefore, the magnetizing yoke requires an elaborate design. The finite element method is the conventional approach used for this purpose, but it is very time consuming. In this article, a neuro-fuzzy method is presented to model the behavior of the magnetizing yoke. Modeling a few different designs with the finite element method and using the results for training the neuro-fuzzy model eradicates the necessity of modeling a huge number of designs with the finite element method. The acquired...

On decomposing complete tripartite graphs into 5-cycles

, Article Australasian Journal of Combinatorics ; Volume 54, Issue 2 , 2012 , Pages 289-301 ; 10344942 (ISSN) Alipour, S ; Mahmoodian, E. S ; Mollaahmadi, E ; Sharif University of Technology

AJC 2012

Abstract

The problem of finding necessary and sufficient conditions to decompose a complete tripartite graph K(r, s, t) into 5-cycles was first considered by Mahmoodian and Mirzakhani (1995). They stated some necessary conditions and conjectured that these conditions are also sufficient. Since then, many cases of the problem have been solved by various authors; however the case when the partite sets r ≤ s ≤ t have odd and distinct sizes remains open. A necessary condition is t ≤ 3r. Billington and Cavenagh (2011) have shown that when r, s, and t are all odd and r ≤ s ≤ t ≤ κr, where κ ≈ 1.0806, then the conjectured necessary conditions for decomposing are also sufficient. We extend this result...

Ultra-sensitive detection of leukemia by graphene

, Article Nanoscale ; Vol. 6, issue. 24 , Dec , 2014 , p. 14810-14819 Akhavan, O ; Ghaderi, E ; Hashemi, E ; Rahighi, R ; Sharif Universit of Technology

2014

Abstract

Graphene oxide nanoplatelets (GONPs) with extremely sharp edges (lateral dimensions ∼20-200 nm and thicknesses <2 nm) were applied in extraction of the overexpressed guanine synthesized in the cytoplasm of leukemia cells. The blood serums containing the extracted guanine were used in differential pulse voltammetry (DPV) with reduced graphene oxide nanowall (rGONW) electrodes to develop fast and ultra-sensitive electrochemical detection of leukemia cells at leukemia fractions (LFs) of ∼10-11 (as the lower detection limit). The stability of the DPV signals obtained by oxidation of the extracted guanine on the rGONWs was studied after 20 cycles. Without the guanine extraction, the DPV peaks...

Specific picomolar detection of a breast cancer biomarker her-2/neu protein in serum: electrocatalytically amplified electroanalysis by the aptamer/peg-modified electrode

, Article ChemElectroChem ; Volume 4, Issue 4 , 2017 , Pages 872-879 ; 21960216 (ISSN) Salimian, R ; Kékedy Nagy, L ; Ferapontova, E. E ; Sharif University of Technology

Wiley-VCH Verlag 2017

Abstract

Specific and sensitive electroanalysis of blood-circulating protein cancer biomarkers is often complicated by interference from serum proteins nonspecifically adsorbing at the biosensing interface and masking specific reactions of interest. Here, we have developed an electrocatalytically amplified assay for specific and sensitive analysis of human epidermal growth factor receptor-2 (HER-2/neu, a protein cancer biomarker over-expressed in breast cancers) that allows us to avoid both the interference from bovine serum albumin (BSA) and electrocatalytic amplification of the signal stemming from the specific aptamer−HER-2/neu binding. A HER-2/neu-specific thiolated aptamer sequence was...