|
|
| |
| Articles
by
Abbas Rezaee |
Total Records (
9 ) for
Abbas Rezaee |
|
 |
| |
|
| |
S.B. Mortazavi
,
A. Safari
,
A. Khavanin
,
A. Kazemnejad
,
S.M. Moazzeni
and
Abbas Rezaee
|
| |
Increasing applications of microwave radiation are of great concern with regard to public health. Several studies have been conducted detect effects of microwave exposure genetic material leading to negative or questionable results. The Micronucleus (MN) assay which is proved to be a useful method for detection of radiation exposure- induced cytogenetic damage was used in present study to investigate the genotoxic effect of microwave and toluene alone and in combination in balb/c lymphocytes. The electromagnetic field with two frequencies (980, 950 MHz, 200 KHz Mod), 5 w and 500 ppm Toluene applied for two weeks. Microwave irradiation had no significant effect on frequency of micronucleus induced, but exposure of animals to toluene alone and in combination with microwave have significantly increased the induced micronucleus (p <0.05). Indeed combination exposure of microwave and toluene showed higher rate of micronucleus in comparison with toluene alone. This study indicated that microwave radiation can not induce any significant cytogenetic effects but, in combination with toluene could show synergistic effect. |
|
|
| |
|
| |
Abbas Rezaee
,
Sanaz Solimani
and
Mehdi Forozandemogadam
|
| |
Acetobacter xylinum has the ability to produce cellulotic biofilms. Bacterial cellulose is expected to be used in many industrial or biomedical materials for its unique characteristics. A. xylinum contains a complex system of plasmid DNA molecules. A 44 kilobases (kb) plasmid was isolated in wild type of A. xylinum. To improve the cellulose producing ability of A. xylinum, role of the plasmid in production of cellulose was studied. The comparisons between wild type and cured cells of A. xylinum showed that there is considerably difference in cellulose production. In order to study the relationship between plasmid and the rate of cellulose production, bacteria were screened for plasmid profile by a modified method for preparation of plasmid. This method yields high levels of pure plasmid DNA that can be used for common molecular techniques, such as digestion and transformation, with high efficiency. |
|
|
| |
|
| |
Abbas Rezaee
,
Mohammad Taghi Ghaneian
,
Sayed Jamalodin Hashemian
,
Gholamreza Moussavi
,
Ali Khavanin
and
Ghader Ghanizadeh
|
| |
Photo-oxidation of dyes is a new concern among researchers since it offers an attractive method for decoloration of dyes and breaks them into simple mineral forms. An advanced oxidation process, UV/H2O2, was investigated in a laboratory scale photoreactor for decolorization of the Reactive blue 19 (RB19) dye from synthetic textile wastewater. The effects of operating parameters such as hydrogen peroxide dosage, pH, initial dye concentration and UV dosage, on decolorization have been evaluated. The RB19 solution was completely decolorized under optimal hydrogen peroxide dosage of 2.5 mmol L-1 and low-pressure mercury UV-C lamps (55 w) in less than 30 min. The decolorization rate followed pseudo-first order kinetics with respect to the dye concentration. The rate increased linearly with volumetric UV dosage and nonlinearly with increasing initial hydrogen peroxide concentration. It has been found that the degradation rate increased until an optimum of hydrogen peroxide dosage, beyond which the reagent exerted an inhibitory effect. From the experimental results, the UV/H2O2 process was an effective technology for RB19 dye treatment in wastewater. |
|
|
| |
|
| |
Ali Khavanin
,
Parvin Najafi
,
Abbas Rezaee
,
Hossin Bakhtou
and
Mehdi Akbari
|
| |
A rapid worldwide expansion of mobile telephones raises questions regarding possible effects of the emitted radiofrequencies on the health of the consumers. The mobile phone system (GSM-900) works in the range of 890-960 MHZ in the electromagnetic spectrum. The present study was performed to investigate the effect of mobile phone radiation on auditory system of rabbit. The auditory brainstem response (ABR), was studied before and after using a mobile phone in the hearing of rabbit. After measuring of click and tone burst at different frequencies (500, 1000, 2000, 4000 and 8000 HZ) with two intensities of 70 and 100 dB, the animals were exposured to electromagnetic waves from a simulator of mobile phone one week exposure and 16-19 h rest. The ABR tests were shown that the latency time of wave V (ms) have some changes in the frequencies of the experiments. The latency time of wave V (ms) at the frequencies of 500 and 1000 HZ was almost unchanged, but at the frequencies of 2000, 4000 and 8000 HZ were decreased at the end of second week of exposure. Statistical analysis have not any significant changes between time latency of wave in pre and post exposures. |
|
|
| |
|
| |
Abbas Rezaee
,
Majid Ansari
and
Reza Shahpori
|
| |
The efficacy of co-trimazine was studied in vitro in mouse macrophages infected with Brucella abortus. The macrophages first were allowed to phagocytes the Brucella abortus. After uptake period, extra cellular bacteria were removed by gentamicin. The bacteria were able to grow in the cells with an apparent multiplication rate of about 90min. Bactericidal activity was measured after treatment of the macrophages with co-trimazine. Co-trimazine showed a bactericidal effect at MIC concentration used, (6.32 mg L-1 trimethoprim and 8.19 mg L-1 sulphadiazine) and a total killing of intracellular bacteria at concentrations of 9.33 mg L-1 trimethoprim and 12.46 mg L-1 sulphadiazine). Results of the study show that co-trimazine was effective on intracellular Brucella abortus. |
|
| |
|
| |
Abbas Rezaee
and
Qurban Behzadiannejad
|
| |
Listeria monocytogenes is a facultative, intracellular, gram positive bacterium that is responsible for sever infections, including prenatal infections, septicemia and meningoencephalitis in humans and a wide variety of animal species. In this study, efficacies of co-trimazine in an immunosuppressed mouse model of listeriosis was compared with co-trimoxazole. After treatment with co-trimazine (400 mg kg-1 of sulphadiazine and 80 mg kg-1 of trimethoprim) every 12 h for 3 days, Listeria monocytogenes could not recovered from the livers of the mice. In contrast, after treatment with co-trimoxazole (400 mg kg-1 sulphamethoxazole and 80 mg of trimethoprim) every 12 h for 3 days, a mean of 3 x 103 colony-forming unit (CFU) was recovered from the livers of mice. Results showed that antibacterial efficacy of co-trimazine was more than co-trimoxazole in experimental infections with Listeria monocytogenes. |
|
|
| |
|
| |
Abbas Rezaee
,
Bahman Ramavandi
and
Faezeh Ganati
|
| |
Mercury has been used in many industries and the removal of mercury ions from waste waters is significant. Biosorption equilibrium of mercury ions to algae biomass was studied in a batch system with respect to temperature and initial metal ion concentration. Langmuir isotherm models was applied to experimental equilibrium data of mercury biosorption. The maximum adsorption of mercury ions on algae biomass was observed at pH 4.0. The biosorption of mercury ions by the algae biomass increased as the initial concentration of the mercury ions increased in the biosorption medium. Biosorption equilibrium was established in about 60 min and the equilibrium was well described by the Langmuir biosorption isotherms. The biomass could be regenerated using 0.1 M HCl, with up to 98% recovery, which allowed the reuse of the biomass in two biosorption-desorption cycles without any considerable loss of biosorption capacity. The functional groups involved in mercury biosorption were identified using spectroscopy analysis. Spectroscopic analysis of algal biomass revealed the presence of amino, carboxyl, hydroxyl and carbonyl groups, which were responsible for biosorption of mercury ions. |
|
|
| |
|
| |
Abbas Rezaee
,
Jamshid Derayat
,
Hatam Godini
and
Gholamhossin Pourtaghi
|
| |
The aim of this research is to study the adsorption of mercury from
aqueous media by an Acetobacter xylinum biofilm. Effects of pH,
adsorption time, initial concentration and the adsorbent dosages on the
adsorption of mercury were studied. The influence of pH on the adsorption
onto the biofilm was studied in the pH range. The surface charge density
varied with pH and the concentration of mercury adsorbed significantly
increased from pH 5.0 to maximum levels at pH 8.0. Adsorption equilibrium
was established after about 50 min, after which point the level of adsorbed
mercury did not significantly change with time. The adsorption equilibrium
was also represented with Langmuir and Freundlich adsorption isotherms.
The adsorption capacity was 180 mg g-1. Desorption studies
were performed with hydrochloric acid. The results suggest that an Acetobacter
xylinum biofilm could be used as an effective adsorbent for the removal
of mercury. |
|
| |
|
| |
Abbas Rezaee
,
Hatam Godini
,
Nayara Naimi
,
Hossin Masombaigi
,
Ahmadreza Yazdanbakhsh
,
Gholamreza Mosavi
and
Anoshiravan Kazemnejad
|
| |
An up-flow packed bed reactor has been operated to investigate the
technical feasibility of biological nitrate removal applied to the synthetic
solution. This study was evaluated Microbial Cellulose (MC) as a biopolymer
carrier in a laboratory bioreactor. The effects of nitrate content and
flow rate on the nitrate removal performance of a MC packed bed bioreactor
have been investigated. Ethanol was used as a carbon source for biological
denitrification. It was found that up to 500 mg L-1 nitrate
concentration the present system is able to produce an effluent with nitrate
content below 10 ppm at 3 h hydraulic retention time. The highest observed
denitrification rate was 4.57 kg NO3-N/(m3 day)
at a nitrate load of 5.64 kg NO3-N/(m3 day). The
removal efficiencies higher than 90% were obtained for loads up to 4.2
kg NO3-N/(m3 day). A mass relation between COD consumed
and NO3-N removed by 2.82 was observed. This continuous flow
pilot bioreactor proved an efficient denitrification system with a relatively
low retention time. |
|
|
|
|
| |
|