Jelvehgari M.,Tabriz University of Medical Sciences |
Montazam S.H.,Islamic Azad University at Bonab
Jundishapur Journal of Natural Pharmaceutical Products | Year: 2012
Background: Microencapsulation is a useful method to prolong a drug release from dosage forms and to reduce its adverse effect (1) among various available methods. The microencapsulation of hydrophilic active ingredients requires the use of a polar dispersing phase such as a mineral oil. Acetone/paraffin systems are conventionally used. Objectives: The current study aimed to investigate two different microencapsulation techniques comparatively, water in oil in oil (w/o/o) and oil in oil (o/o), for theophylline (TH) loaded ethylcellulose (EC), cellulose acetate butyrate (CAB), Eudragit RS and RL mi-crospheres with regard to loading efficiency, release and degradation kinetics. Materials and Methods: Microspheres were prepared by the emulsification method by solvent diffusion/evaporation technique and different polymers which were incorporated into microspheres to control the release rate of drug. Theophylline (TH) was chosen as a model drug. The emulsion technique was investigated for to prepare theophylline microparticles. EC and CAB and acrylatemethacrylate copolymer corresponding to the above ratios were selected as microparticles wall materials. The effects of type polymers on the physical characteristics and dissolution of the microparticles were also studied. However, the TH loading efficiency (for w/o/o emulsion about 90.64% and o/o emulsion about 73.90/5 to 95.90%) and the TH release kinetics were influenced by the microencapsulation technique. Results: The results demonstrated that the o/o microspheres (containing of CAB) was most appropriate, providing a high encapsulation efficiency (95.90%) and low initial burst release (6.45%). The microspheres prepared with CAB polymer showed faster dissolution rate than other polymers with 0.75:1 drug to polymer ratio. The double emulsion technique with EC as wall material gave the high dissolution efficiency (80.48%) of microcapsules. Conclusions: Eudragit RS microspheres showed higher yield (90%). The release of TH from CAB and Eudragit RL walled microcapsules was slow whilst the release from those of EC and Eudragit RS were faster. The type of polymer and the drug to polymer ratio were found to be the key factors affecting the release profile which could lead to micro-spheres with desired release behavior. © 2012 School of Pharmacy, Ahvaz Jundishapur University of Medical Sciences; Published by Kowsar Corp.
Rad A.,Amirkabir University of Technology |
Naderi B.,Amirkabir University of Technology |
Soltani M.,Islamic Azad University at Bonab
Expert Systems with Applications | Year: 2011
Although all university majors are prominent, and the necessity of their presence is of no question, they might not have the same priority basis considering different resources and strategies that could be spotted for a country. Their priorities likely change as the time goes by; that is, different majors are desirable at different time. If the government is informed of which majors could tackle today existing problems of world and its country, it surely more esteems those majors. This paper considers the problem of clustering and ranking university majors in Iran. To do so, a model is presented to clarify the procedure. Eight different criteria are determined, and 177 existing university majors are compared on these criteria. First, by k-means algorithm, university majors are clustered based on similarities and differences. Then, by AHP algorithm, we rank university majors. © 2010 Elsevier Ltd. All rights reserved.
Sanayei A.,Wayne State University |
Farid Mousavi S.,University of Tehran |
Yazdankhah A.,Islamic Azad University at Bonab
Expert Systems with Applications | Year: 2010
During recent years, how to determine suitable suppliers in the supply chain has become a key strategic consideration. However, the nature of supplier selection is a complex multi-criteria problem including both quantitative and qualitative factors which may be in conflict and may also be uncertain. The VIKOR method was developed to solve multiple criteria decision making (MCDM) problems with conflicting and non-commensurable (different units) criteria, assuming that compromising is acceptable for conflict resolution, the decision maker wants a solution that is the closest to the ideal, and the alternatives are evaluated according to all established criteria. In this paper, linguistic values are used to assess the ratings and weights for these factors. These linguistic ratings can be expressed in trapezoidal or triangular fuzzy numbers. Then, a hierarchy MCDM model based on fuzzy sets theory and VIKOR method is proposed to deal with the supplier selection problems in the supply chain system. A numerical example is proposed to illustrate an application of the proposed model. © 2009.
Hosseini Hashemi B.,The Intl Institute of Earthquake Engineering and Seismology IIEES |
Poursamad Bonab A.,Islamic Azad University at Bonab
Engineering Structures | Year: 2013
In this study, the cyclic behavior of laced built-up columns was investigated. Eight columns, for which two IPE100 profiles were used as the longitudinal elements (chords) and plates were used as the lacing bars, were constructed and tested under constant axial load and lateral cyclic load. To evaluate the effects of the axial load, different axial loads were exerted on the specimens. To evaluate the effects of varying the distance between chords, two different distances were used in the test specimens. The test results showed that the axial load significantly affected the ductility, the strength and the stiffness of the built-up columns. The different distances between the main chords of the columns changed the ductility but had little effect on the strength, stiffness and energy absorption capacity. The test results showed that the laced columns exhibited relatively good seismic characteristics, and it may be acceptable to use these types of columns in moderate earthquake-prone areas. © 2013 Elsevier Ltd.
Abbasian M.,Payame Noor University |
Shoja S.E.,Islamic Azad University at Bonab
Brazilian Journal of Chemical Engineering | Year: 2012
'Living' radical graft polymerization was employed to prepare graft copolymers with nitroxidemediated arylated syndiotactic polystyrene as the backbone and polystyrene (PS), poly(p-methylstyrene) (PMS) and poly(methylmethacrylate) (PMMA) as branches. A two-stage process has been developed to synthesize the macroinitiator. First, syndiotactic polystyrene (sPS) was modified by the Friedel-Crafts reaction to introduce chlorine; second, the chlorine groups were converted to nitroxide mediated groups by coupling with 1-hydroxy-2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO-OH). The resulting macroinitiator (sPSTEMPO) for 'living' free radical polymerization was then heated in the presence of styrene and pmethylstyrene to form graft and block copolymers. We used the obtained copolymer and N-bromosuccinimide as brominating agent to achieve polymers with bromine groups. This brominated copolymer was used as a macroinitiator for polymerizing methyl methacrylate in the presence of the CuBr/bpy catalyst system. The formation of the graft and block copolymers was confirmed by DSC, 1H NMR and FTIR spectroscopy. This approach using macroinitiators is an effective method for the preparation of new materials.
Ghorbian S.,Islamic Azad University at Bonab
Gene | Year: 2012
Male factor infertility elucidated about half the couple of infertility and in around 50% of cases, its etiology remains unknown. The aim of this study was to investigate a predisposing genetic background for Yq deletions and male infertility and effectiveness of molecular genetic approaches have uncovered several etiopathogenetic factors, such as microdeletions of Yq chromosome. The Y chromosome microdeletions removing the azoospermia factor (AZF) regions, which are most common molecular genetic causes of oligospermia or azoospermia. However, with the analysis of Yq deletions, we are able to obtain a better understanding of the clinical significance of genetic anomaly and to the identifying of fertility candidate genes in the AZF regions. Molecular genetic approaches, becomes a routine diagnostic test, that provides an etiology for spermatogenic disturbances, and prognosis for testicular sperm retrieval according to the type of deletion. © 2012 Elsevier B.V.
Ghorbian S.,Islamic Azad University at Bonab
International Journal of Infertility and Fetal Medicine | Year: 2012
Cell-free fetal DNA (cffDNA) is available in the maternal circulation throughout pregnancy and can be used for noninvasive prenatal diagnosis including, determination of fetal sex, identification of specific single gene disorders, typing of fetal blood groups (RhD), paternity determination and potentially routine use for Down's syndrome (DS) testing of all pregnancies.I searched published literature on the PubMed and databases on Scopus interface systematically using keyword's cffDNA, noninvasive diagnosis, fetal DNA in the maternal serum. Reference lists from the papers were also searched. cffDNA representing only 3% of the total cell-free circulating DNA in early and rising to 12% in late pregnancy, clinical investigations has already demonstrated the potential advantage, such as improving safety, earlier diagnosis and comparative ease of testing using cffDNA technology. The discovery of cffDNA circulating in the maternal serum has opened the door to noninvasive prenatal diagnosis testing with novel clinical implications.
Vahedi M.,Payame Noor University |
Irani F.N.H.A.,Islamic Azad University at Bonab
Procedia Computer Science | Year: 2011
Information Technology (IT) is one for the issues that divides the world. There is an ongoing lively debate about the role that information technology can play for knowledge management. Information technology is used pervasively in organizations, and thus qualifies as a natural medium for the flow of knowledge. The best way of applying information technology to knowledge management is probably a combination of two factors: on the one hand, the awareness of the limits of information technology, and of the fact that any IT deployment will not achieve much, if it is not accompanied by a global cultural change toward knowledge values; on the other hand, the availability of information technologies that have been expressly designed with knowledge management in view. Knowledge has been lately recognized as one of the most important assets of organizations. Can information technology help the growth and the sustainment of organizational knowledge? The answer is yes, if care is taken to remember that IT here is just a part of the story (corporate culture and work practices being equally relevant) and that the information technologies best suited for this purpose should be expressly designed with knowledge management in view. © 2010 Published by Elsevier Ltd.
Kia K.K.,Islamic Azad University at Bonab |
Bonabi F.,Islamic Azad University at Bonab
Review of Scientific Instruments | Year: 2012
A simple and low cost apparatus is reported to produce multiwall carbon nanotubes and carbon nano-onions by a low power short pulsed arc discharge reactor. The electric circuitry and the mechanical design details and a micro-filtering assembly are described. The pulsed-plasma is generated and applied between two graphite electrodes. The pulse width is 0.3 μs. A strong dc electric field is established along side the electrodes. The repetitive discharges occur in less than 1 mm distance between a sharp tip graphite rod as anode, and a tubular graphite as cathode. A hydrocarbon vapor, as carbon source, is introduced through the graphite nozzle in the cathode assembly. The pressure of the chamber is controlled by a vacuum pump. A magnetic field, perpendicular to the plasma path, is provided. The results show that the synergetic use of a pulsed-current and a dc power supply enables us to synthesize carbon nanoparticles with short pulsed plasma. The simplicity and inexpensiveness of this plan is noticeable. Pulsed nature of plasma provides some extra degrees of freedom that make the production more controllable. Effects of some design parameters such as electric field, pulse frequency, and cathode shape are discussed. The products are examined using scanning probe microscopy techniques. © 2012 American Institute of Physics.
Kazemi Kia K.,Islamic Azad University at Bonab |
Bonabi F.,Islamic Azad University at Bonab
Thin Solid Films | Year: 2013
In this work different hydrocarbons are used as the carbon source, in the production of carbon nanotubes (CNTs) and nano onions. An electric field induced needle pulse arc-discharge reactor is used. The influence of starting carbon on the synthesis of CNTs is investigated. The production efficiency is compared for Acetone, Isopropanol and Naphthalene as simple hydrocarbons. The hydrocarbons are preheated and then pretreated by electric field before being exposed to plasma. The hydrocarbon vapor is injected into plasma through a graphite spout in the cathode assembly. The pulsed plasma takes place between two graphite rods while a strong electric field has been already established alongside the electrodes. The pulse width is 0.3 μs. Mechanism of precursor decomposition is discussed by describing three forms of energy that are utilized to disintegrate the precursor molecules: thermal energy, electric field and kinetic energy of plasma. Molecular polarity of a hydrocarbon is one of the reasons for choosing carbon raw material as a precursor in an electric field induced low power pulsed-plasma. The results show that in order to obtain high quality carbon nanotubes, Acetone is preferred to Isopropanol and Naphthalene. Scanning probe microscopy techniques are used to investigate the products. © 2013 Elsevier B.V.