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Showing 28 results for Farokhi


Volume 4, Issue 3 (Summer 2018)
Abstract

Aims: Transportation of clinical samples and long-term recoverability of fungal strains are critical to epidemiological studies. In addition, the study of fungi often requires the use of living pure cultures. The aim of this study was to evaluate the methods used to preserve culture collections of dermatophytes, consisted of storage in sterile distilled water, cryopreservation with glycerol, preserving in tryptic soy broth (TSB), and freezing mycobiotic agar.
Materials and Methods: in this experimental study, ninety-two dermatophyte isolates belonged to 10 species were tested. The freezing protocol was done in 4 forms of sterile distilled water, cryopreservation with glycerol, freezing mycobiotic agar, and preserving in TSB. The viability of the dermatophytes species was assessed after 3 years at morphological (macro and microscopic features), physiological (Using Dermatophyte Test Medium; DTM, urease test media, and the hair perforation test), and genetic levels by restriction fragment length polymorphism (RFLP).
Findings: The survival rate was 84 out of 92 water stored fungal strains (91.3%) and 81 out of 92 mycobiotic agar stored strains (88.0%) and 75 out of 92 glycerol 40% stored strains (81.5%) and 43 out of 92 TSB stored fungal strains (46.7%). Overall, more than 88% of the strains survived in the distilled water storage and freezing mycobiotic agar, methods, while storage in TSB had the least success in the maintenance of dermatophytes.
Conclusion: The procedure to preserve cultures in sterile distilled water is reliable, simple, and inexpensive.


Volume 6, Issue 4 (Fall 2020)
Abstract

Background: Aureobasidin A is known as a cyclic depsipeptide antibiotic with toxic effects against yeasts such as Candida spp at low concentration. Combination therapy is used as a conventional treatment for fungal infections, especially drug-resistant cases. The current study aimed to investigate the combined effects of fluconazole and Aureobasidin A on fluconazole-resistant C. albicans isolates using broth microdilution method.
Materials & Methods: Antifungal activity of Aureobasidin A (AbA) compared to fluconazole against C. albicans ATCC 76615 strain was determined using the standardized broth microdilution method according to the Clinical and Laboratory Standards Institute (CLSI, document M27-Ed4) guidelines. The checkerboard method was used to test the combined effects of Aureobasidin A and fluconazole. The synergy, indifference, and antagonism were defined based on the fractional inhibitory concentration values below 0.5, 0.5-4, and more than 4 μg/mL, respectively.
Findings: MIC50 and MIC90 evaluations of Aureobasidin A and fluconazole were done at concentrations of 0.25-2 and 32-64 μg/mL against C. glabrata isolates, respectively. The synergy between fluconazole and Aureobasidin A was observed against Candida isolate. A reduced MIC was demonstrated against C. albicans isolate when fluconazole was combined with Aureobasidin A at 4 to 0.12 μg/mL concentrations.
Conclusion: The present study findings revealed that Aureobasidin A combined with fluconazole exhibited potent inhibitory effects against fluconazole-resistant C. albicans isolates. Further studies is recommended to investigate the synergistic effects of Aureobasidin A and other antifungal drugs.

 

Volume 8, Issue 1 (Winter 2022)
Abstract

Backgrounds: Aspergillus fumigatus is a pathogen responsible for invasive aspergillosis and the main leading cause of death in immunosuppressed individuals. The present study aimed to evaluate the impact of eugenol-loaded chitosan nanoparticles on the expression of CYP51a and CYP51b, two well-known genes responsible for triazole drug resistance in A. fumigatus.
Materials & Methods: The minimum inhibitory concentration (MIC) of eugenol-loaded chitosan nanoparticles, chitosan, eugenol, and itraconazole was determined based on the Clinical and Laboratory Standards Institute M38-E3 method at concentrations of 4.6-2400, 11.7-12000, 2-2048, and 1-256 μg/mL, respectively. The expression of CYP51A and CYP51B was evaluated in A. fumigatus exposed to 0.5, 1, and 2× of MIC concentration of NPs and itraconazole using the real-time polymerase chain reaction.
Findings: The obtained results showed that eugenol-loaded chitosan nanoparticles sucessfully reduced A. fumigatus fungal growth at 300 μg/mL concentration. MIC of chitosan, eugenol, and itraconazole was measured to be 6000, 256, and 4 μg/mL, respectively. The results of real-time PCR also revealed that eugenol-loaded chitosan nanoparticles increased the expression of both CYP51A and CYP51B in a dose-dependent manner. The expression of fungal CYP51A and CYP51B at mRNA level was significantly increased 1.26, 1.93, and 3.1-fold as well as 1.2, 2.1, and 2.4-fold at concentrations of 150, 300, and 600 μg/mL, respectively (p<.05). However, it seems that the prepared nanoparticles had a lower impact on the expression of these genes compared to itraconazole.
Conclusion: Overall, these findings suggest that the treatment of A. fumigatus with eugenol-chitosan nanoparticles could increase the expression of the CYP51 gene, suggesting the anti-fungal property of these nanoparticles.

Volume 8, Issue 2 (Spring 2022)
Abstract

Backgrounds: Allium cepa L. as a traditional medicine is a rich source of beneficial bioactive metabolites. In the present study, the effect of A. cepa ethanolic extract (EAC) was studied on Aspergillus fumigatus growth, ergosterol synthesis, gliotoxin production, and gliP gene expression.
Materials & Methods: The minimum inhibitory concentration (MIC) of EAC (125-4000 µg/mL) was determined against A. fumigatus isolates according to Clinical and Laboratory Standards Institute (CLSI) guidelines (M-38). Protease activity, gliotoxin production, cell membrane ergosterol content, ultrastructure, and gliP gene expression were evaluated in the fungus exposed to 0.5× MIC concentrations of EAC (1000 μg/mL) and fluconazole (FCZ: 64 μg/mL).
Findings: Ergosterol content was significantly reduced to 0.53 and 0.45 µg/mg in FCZ- and EAC-treated fungal cells, respectively (p< .001). The protease activity was significantly inhibited in both EAC- and FCZ-treated groups. The gliotoxin production was inhibited by 51.55 and 68.75% in the treated groups with FCZ and EAC, respectively. The expression of gliP in both EAC- and FCZ-treated A. fumigatus groups was significantly reduced by 0.40 and 0.53-fold, respectively (p< .05).
Conclusion: This study finding revealed that A. cepa ethanolic extract (EAC) effectively suppressed the growth and virulence factors of A. fumigatus, which could be attributed in part to its bioactive metabolites. Further studies are recommended to isolate and identify these metabolites as potential candidates for the development of antifungal drugs.

 
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Volume 10, Issue 3 (Fall 2006)
Abstract

The Iraqi Special Tribunal is a body established under the Iraqi national law to try Iraqi nationals or residents accused of genocide, crimes against humanity, war crimes or other serious crimes committed between 1968 and 2003. The statute of Iraqi Special Tribunal was enacted on 10. 12. 2003 by the Iraqi Governing Counsel. The tribunal recognizes the wishes of the Iraqi people to establish a legal instrument suitable for proving their rights and uncovering the truth about what happened during the past years. The intention of the drafters of the statute was to attempt insofar as possible to comply with the international standards of due process of law and to focus on the crimes committed under the international law such as genocide, war crimes and crimes against humanity. But do they success in doing so or not will be discussed in this paper.

Volume 10, Issue 3 (12-2010)
Abstract

Abstract Fatigue can be expressed as the failure of asphalt concrete under repeated loading in such a way that stress induced in the asphalt layer could be less than ultimate strength of the material. Fatigue cracking in asphalt concrete layer can be classified into two types regarding the place of crack initiation and the type of crack propagation. The first type the cracks initiated in the bottom of asphalt layer and propagates upward. This type of cracking is produced in the thin asphalt layer. The second type of cracking which is produced in thick asphalt layer is initiated in surface area then propagates downward which is called Top-Down cracking. The second type of cracking is studied less compared to the first one. One type of fatigue cracking, is fracture mechanics approach in which the failure in asphalt mixture is related to number of repeated loading. In this study the fracture mechanics approach was implemented to understand the effective parameters in propagation of top-down cracking. as well as developing a model to interpret the crack propagation in pavement also some graphs were produced for different types of material and loading which gives the length of cracks versus the number of repeated loading. the results showed that with increasing the load distance from the initial place which is initiated the stress intensity factor is increased in mode Ι and mode ΙΙ. Also increasing the stiffness gradient in asphalt concrete due to temperature differential in top and bottom of asphalt layer or differential increasing between stiffness of asphalt surface and asphalt base course will be increased the stress intensity factor.

Volume 11, Issue 3 (Summer 2020)
Abstract

Glucoamylase, is an important economic enzyme due to its ability to hydrolyze starch and β-D-glucose polymers. Understanding of factors affecting the thermal stability of the glucoamylase enzyme is critical in the production of isoenzymes with high heat or cold stability.  In this study, the effect of temperature on the structure and properties of each of the isoenzymes of the mesophilic, thermophilic and psychrophilic glucoamylase were studied. For this purpose, molecular dynamics simulation was used to assess these factors and structural differences. 240 nanosecond of MD simulation was done for three isoenzymes of glucoamylase in four temperatures at 300, 350, 400 and 450 K. The variations of each of these parameters were compared for three isoenzymes, and it was found that among the computable factors in molecular dynamics simulation, electrostatic energy of protein with water, van der Waals energy between proteins and water, free energy solubility (∆Gsolvation), instability parameter, nonpolar solvent accessible surface, and total solvent accessible surface can be used to predict thermal stability of a protein during increase of temperature.
 

Volume 12, Issue 2 (6-2009)
Abstract

Objective: The greatest challenge in cancer gene therapy is to achieve the high specificity and efficiency in targeting of cancer cells. Because the goal of cancer gene therapy is to eradicate cancer cells, many therapeutic genes could be detrimental if unintentionally expressed in normal cells. Using promoter of the genes which are expressed specifically in cancer cells or have much more expression in cancer cells than normal cells, is very noticeable tool in cancer gene therapy (CGT). In this study we were searching for cancer specific promoter which could highly express therapeutic gene. Materials and methods: In order to apply a cancer specific promoter for creating a CGT construct, a promoter which have 34% similarity to Survivin core promoter was amplified from human genome by using Nested-PCR. Survivin is a member of anti-apoptotic gene and its over-expression was observed in up to 70% of breast cancers. This gene fragment contains two transcriptional binding sites which were similar to Survivin promoter according to the evaluation of Promoter Scan, EPD, Transfac, Compel and TRRD program. These binding sites were recognized by STAT1 and E2F transcription factors. This promoter was cloned into pCDNA3.1/Hygro+ plasmid in along with hypoxia and estrogen modules and pro-apoptotic gene tBid. Results: Semi-quantitative RT-PCR results of transfected cancer cells showed that this gene fragment (Survivin like promoter) have relatively same potential as CMV promoter to direct tBid gene expression. Conclusion: Utilization of chimeric promoter containing Survivin like promoter could be a promising tool in killing cancer cells naturally by inducing apoptosis. This construct is highly effective in transcriptional targeting of tBid in comparison to control construct.

Volume 12, Issue 4 (10-2010)
Abstract

Objective: Nowadays, as the field of neural tissue engineering advances, the fabrication and application of combined structures open a new window of research for the regeneration of nervous system injuries. In this study, chitosan/poly(vinyl alcohol)-carbon nanotube nanocomposites has been exploited as scaffolds. Materials and Methods: Electrospinning was used to fabricate chitosan/poly(vinyl alcohol)-carbon nanotube scaffolds. Raman spectroscopy and scanning electron microscopy (SEM) was used to evaluate the chemical and physical structure of the electrospun scaffolds. Then, the biocompatibility of the scaffolds was evaluated using MTT assay and Neutral red assay. Results: The results showed that the chitosan/poly(vinyl alcohol)-carbon nanotube nanocomposites have suitable structural and morphological aspects for human brain-derived cells growth and proliferation. Therefore, the cells could maintain their usual morphology while adhering to the surface of the nanocomposites due to an appropriate biocompatibility of the scaffolds. Conclusion: Chitosan/poly(vinyl alcohol)-carbon nanotube nanocomposites could enhance the proliferation of human brain-derived cells due to their proper structure and biocompatibility.

Volume 13, Issue 50 (5-2016)
Abstract



Volume 15, Issue 1 (3-2015)
Abstract

When two bodies slide on each other, friction is created. By superposing ultrasonic oscillation to one of the bodies, the friction force is reduced .This phenomenon is widely used in metal forming and metal cutting. For the production and transmission of ultrasonic vibrations to a target it is required to use an ultrasonic system the components of which are a generators, a transducers and a horn. Horn constitutes an important part of the Ultrasonic systems. The main task of the horn is to transmit the ultrasonic vibrations and amplify the ultrasonic vibration amplitude at the output. In this study, an Aluminum horn was designed in cylindrical-conical-cylindrical shape geometry and was analyzed by the finite-element method(FEM) using the Abaqus software was manufactured. The resonance frequency obtained in Abaqus was equal to 19976 Hz. The resonance frequency obtained from the generator was equal to 19920 Hz. Hence there is a very good agreement between the experimental result and the FEM simulation. The difference between the finite element simulation results and the experimental ones is less than one percent. Moreover, a horn –workpiece assembly for applying the ultrasonic sliding friction was designed and manufactured. Then the fixture and the tool holder clamp were designed for the vibrating tool so that it can be installed on a milling machine and the friction force measurement is possible while the ultrasonic vibrations are applied.

Volume 15, Issue 3 (5-2015)
Abstract

In this paper the design and manufacturing of Iosipesque shear test fixture modification evaluated. This shear test Fixture by applying the shear load in layered of composites specimens can predict the mechanical properties of composite materials in mode II of fracture.In this paper, first, a common traditional Iosipesque shear test fixture according to the standard was manufactured. Then, by applying shear load on polymer-based composites (carbon-epoxy) and wood (a natural composite) specimens, bugs of the traditional fixture were found.Finally by 6 fundamental Modification of the fixture structure, the new design was proposed. It was also found that by applying these reforms, both of concentrating the shear force (in the shear zone) and test accuracy has been increased. Accordingly, after the construction and testing of new fixture on wood and polymer based composite specimens and by applying the standard deviation’s equations, the standard deviation of the modified fixture for wood and polymer based composite has ben reduced 82.7% and 48% respectively, that suggesting the accuracy of the fixture. In addition, fluctuations of the fixtures diagram of the new design also significantly reduced.

Volume 15, Issue 9 (11-2015)
Abstract

When two bodies slide on each other the asperities are engaged and friction is created. By superposing ultrasonic vibrations to one of the bodies, the friction force is reduced .This phenomenon is widely used in metal forming and metal cutting. In this research, experimental study of the effect of ultrasonic vibrations has been on sliding friction force in longitudinal direction. For this purpose, set-up was designed and fabricated. The main components of the set-up, including generators, transducers, first engaged body and second engaged body. The Set-up was installed on the machine lathe for investigation of the effect of ultrasonic vibrations on sliding friction force in longitudinal direction. The experiments were performed for eight different performance conditions. Next, the effect of each parameter ultrasonic wave velocity, roughness and material of contact surfaces were studied on the reduction of the friction force due to addition of ultrasonic vibrations. The result show that range of reduction friction force due to addition of ultrasonic vibrations in longitudinal direction is between 40 to 100% for the different performance conditions also friction force significantly reduced by increasing ultrasonic wave velocity so that friction force can be brought to zero by significant increase in ultrasonic wave velocity. The results also show that friction force has a more reduction for the surface has a less roughness. Aluminum-aluminum surfaces can be more reduction friction force from aluminum – steel surfaces.

Volume 16, Issue 2 (9-2013)
Abstract

Objective: The prevalence of respiratory allergies, especially those induced by fungi such as Alternaria alternata, has dramatically increased over the past decade. This increase has caused major health problems worldwide. This study aimed to investigate the role of A. alternata in the etiology of allergic asthma, by using the skin prick test and assessment of IgE specific to the fungus in the patient's sera. Methods: This study enrolled 202 patients with allergic asthma, aged 12 to 83 years. Participants included 40.1% males and 59.9% females who were enrolled after recording demographic information. A skin prick test with the whole cellextract of A. alternata was performed on the epidermis of the patients' forearms. Histamine and normal saline were used as positive and negative controls, respectively. Serum levels of IgE specific for A. alternata were measured for all patients using the ImmunoCAP Phadiatop method in which the specific A. alternata allergen cocktail that connected to the solid phase reacted to IgE antibodies in each patient's sera. Data were analyzed by analysis of variance and chi-square tests. Results: Among 202 patients with allergic asthma, 14 (6.93%) had mild asthma, 73 (36.10%) were moderate asthmatics and 115 (56.90%) had severe asthma. In total, 14 (6.93%) patients were positive for both the skin test and IgE specific to A. alternata, 35 (17.33%) had negative specific IgE and positive skin test results, and 36 (17.82%) had a positive specific IgE and negative skin test. A total of 117 (57.92%) patients were negative for both tests. Conclusion: The results of this study showed the presence of IgE specific for A. alternata in 50 of 202 (24.75%) patients diagnosed with allergic asthma. The skin prick test was successfully used as a screening test. The results were further confirmed by solid-phase immunoassay of the IgE specific for A. alternata crude allergenic extract.

Volume 16, Issue 3 (12-2013)
Abstract

Objective: Fusarium species are prevalent contaminants of foodstuffs and agricultural crops.  They produce fumonisins, which are carcinogenic mycotoxins. The present study has evaluated maize and wheat samples from ten provinces in Iran that were contaminated with Fusarium species. Special attention was paid to the ability of the isolates to produce fumonisin B1 (FB1) as a public health hazard. Methods: We collected 32 maize and 15 wheat samples from ten provinces that were major cultivation areas. Samples surface disinfected with a 1% sodium hypochlorite solution for 2 minutes. Fusarium species were isolated by the flotation method on malachite green agar. Pure cultures on potato dextrose agar (PDA) were identified using a combination of macroscopic and microscopic morphological criteria. The ability of the isolates to produce FB1 was evaluated by thin layer chromatography (TLC) and the amounts of fumonisin B1 produced were assessed by high performance liquid chromatography (HPLC). Results: A total of 55 Fusarium isolates that belonged to five species were isolated. There were 27 of the 32 maize samples (84.4%) and 11 of 15 wheat samples (73.3%) that were contaminated with Fusarium species. Species consisted of F. verticillioides (23 isolates), F. proliferatum (22 isolates), F. subglutinans (5 isolates), F. nygamai (4 isolates) and F. redolens (1 isolate) based on morphological criteria. Twenty-two of the 55 (40%) Fusarium isolates produced FB1 in a total range from 230.4 to 9565 µg/ml. The highest amounts of FB1 production were related to toxigenic isolates of F. verticillioides and F. proliferatum. Conclusion: Results of the present work indicates a high degree of contamination of maize and wheat with Fusarium strains that belong to the Gibberella fujikuroi species complex وparticularly F. verticillioides and F. proliferatum. This contamination is a potential public health threat due to food spoilage and subsequent production of high levels of carcinogenic FB1.

Volume 16, Issue 9 (11-2016)
Abstract

This paper deals with studying and developing a proper constitutive model for liver tissue. For this purpose, deformation of liver in uniaxial compression, for two different strain rates, is analytically and numerically studied, based on both hyperelastic and hyperviscoelastic constitutive models. Both of the models are based on a polynomial-form energy function. The stress-strain curves, for uniaxial compression, obtained from these models, have been fitted to the existing experimental data to determine the model coefficients. Moreover the models are examined in uniaxial tension and pure shear loadings. ABAQUS commercial software, in which both of the models are available, has been used for numerical simulations. Then, to evaluate the computational analyses, analytical and numerical results have been compared with each other and also with the existing experimental data. The results show that the presented analytical solution and FE simulation are very close together and also both are accurate enough, compared with the experimental data and an acceptable stability is observed. Furthermore the effect of friction coefficient between the sample and the compressing plate in uniaxial compression test has been investigated. FE simulation results show that the stress will increase with increasing friction coefficient. This implies that friction coefficient must be carefully selected to accurately describe the tissue’s response. Compared with previously published researches on other tissues, the constitutive models adopted here to predict liver behavior is mathematically more complex due to non-zero material constants. Analytical solution of these constitutive models is, in fact, the main challenge and innovation of this paper.

Volume 16, Issue 95 (January 2019)
Abstract

Folic acid is one of the essential vitamins that deficiency of it causes congenital malformations in pregnant, especially neural tube disorders. Since the human body cannot synthesize this vitamin, enrichment process on bread that is known as one of the most widely consumed foods in the diet of our people, can be on an effective step for eliminating defects caused by vitamin’s deficiency in people. Considering the health effects of wheat bran and and the presence of folic acid in it, in this study attempts to fortify flour (with 7% wheat bran) by 100% RDI folic acid and then measuring the stability of folic acid in bread making process by HPLC method and microbiological assay. The results indicated that the microbiological assay showed higher amount than the high performance liquid chromatography method because of the ability to measure the natural folate in the samples. Also, during the bread making process, the folic acid and folate content increased during the fermentation process and then decreased by the thermal baking process. The remaining amount of folic acid and folate in the final bread showed the relatively high resistance of this vitamin in the process of Barbariʼs bread, and thus the ability of the bread fortification process to provide folic acid requirements in adults.

Volume 17, Issue 10 (1-2018)
Abstract

Due to unique properties, lattice composite structure are used extensively in aviation, marine and automotive industry. In this research, experimental and numerical investigation of the free vibration of composite sandwich plates with triangular grid has been studied. For the fabrication of this plates, silicone mold, filament winding, and hand lay-up method were used. Stiffened plates and simple plates are fabricated, separately. Then, composite sandwich plates with triangular grid were created by attaching the two parts together. The modal test is done on the plates and natural frequencies have been extracted.The comparison of numerical and experimental results showed that there is a good agreement between them. By using Taguchi method, a parametric study was performed on the vibrational behavior of sandwich plates with triangular cores via three parameters that such as stiffeners’ number, stiffener thickness and skin thickness. The results show that the natural frequency of sandwich plates with triangular grid has a most sensitive to the stiffener thickness, and least sensitive to stiffeners’ number. The sensitivity of natural frequency is almost identical to stiffener thickness and skin thickness.To evaluate the efficiency of sandwich plates with triangular grid, the natural frequency of sandwich plates are compared with simple plates in the different boundary condition. The results show that the natural frequency of sandwich plates with the triangular grid is 133% and 138% higher than an equivalent simple shell at free and clamp boundary condition, respectively.

Volume 18, Issue 4 (8-2018)
Abstract

Due to unique properties, grid stiffened composite cylinder shells are used extensively in aviation, marine and automotive industry. In recent decades, several studies are done to predict the critical buckling load of grid stiffened composite cylinder shells without breakdown or failure. Vibration Correlation Technique (VCT) is one of the most important non-destructive methods that based on nonlinear vibration analysis. The aim of this research is the prediction of the critical buckling load of stiffened composite cylinder shells with lozenge grid by using VCT. For this purpose, linear and nonlinear vibration analysis of composite cylindrical shells were performed in different compressive loads by using finite element software ABAQUS, firstly. In the next step, linear buckling critical load was determined by using numerical methods. Then, non-linear critical buckling load of grid stiffened composite cylinder shells was predicted by using VCT. To validate the results of VCT, five composite cylindrical shells were fabricated by using filament winding method with same conditions and was placed under axial compression test. Finally, the critical buckling load was measured experimentally. The results show that the difference between the critical buckling load of VCT with experimental buckling load is less than 3%. This subject implies that VCT is suitable for prediction of critical buckling load of stiffened composite cylinder shells with lozenge grid with very high accuracy.

Volume 18, Issue 5 (9-2016)
Abstract

In this study, geographical discrimination of some Iranian pomegranate cultivars was investigated using chromatographic analyses and multivariate statistical methods. The organic acid content of 24 pomegranate samples of different cultivars (5 sweet, 7 sweet-sour and 12 sour cultivars) from different production sites (Yazd and Markazi Provinces, Iran) were analyzed by HPLC/UV. Ten organic acids including oxalic, tartaric, malic, shikimic, ascorbic, maleic, succinic, citric, acetic and fumaric were identified and quantified in freshly prepared juices. The total organic acid content was in the range of 105.4–2074.4 mg 100 g-1 of pomegranate juice. Citric acid predominated in most cultivars especially in sour cultivars, while sweet-sour and sweet ones were characterized by high malic acid content. Principal Component Analysis (PCA) indicated that principle component 2 was responsible for discrimination of two geographical regions. Furthermore, Factor Analysis (FA) and Hierarchical Cluster Analysis (HCA) showed the high potential in complete separation of pomegranate cultivars based on geographical origins.

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