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Showing 12 results for Khadem

Monireh Khadem, Farnoush Faridbod, Parviz Norouzi, Abbas Foroushani Rahimi Foroushani, Mohammad Reza Ganjali, Seyed Jamaleddin Shahtaheri, Rasoul Yarahmadi,
Volume 7, Issue 1 (4-2017)
Abstract

Diazinon is commonly used for pest control in the agricultural fields because of its relatively low cost and high efficiency. Due to the increasing application of pesticides, reliable and accurate analytical methods are necessary for their monitoring. This work was aimed to design the high selective electrochemical sensor for determining of diazinon in biological and environmental samples. The composition of sensor was modified with multi-walls carbon nanotubes and a molecularly imprinted polymer (MIP). A diazinon MIP was synthesized and applied in the carbon paste electrode (CP). The prepared sensor was used to determine the concentration of analyte. Parameters affecting the sensor response, such as sample pH, electrolyte concentration and its pH, and the instrumental parameters of square wave voltammetry, were optimized in different levels to select the optimum conditions for analysis of diazinon. The MIP-CP electrode showed very high specificity for determining the analyte. The obtained linear range was 1×10-6 to 5×10-10 mol L-1. The detection limit was 2.7×10-10 molL-1. This sensor was successfully used to determine the diazinon in environmental and biological real samples without special sample pretreatment before analysis.


Reza Jafari Nodoushan, Mohammad Javad Jafari, Gholam Abbas Shirali, Soheila Khodakarim, Hassan Khademi Zare, Amir Abbas Hamed Monfared,
Volume 7, Issue 3 (9-2017)
Abstract

Introduction: Resilience engineering is a novel approache to risk management and is the inherent ability of a system to adapt their work before, during and after the changes and adverse events in such a way that maintain the system performance under predictable and unpredictable conditions. The aim of this study was to identify indicators of organizational resilience of refineries and ranking them using fuzzy TOPSIS technique.  

Material and Method: A qualitative study was done to identify organizational resilience indicators of refinery complex. The main method of data collection was semi-structured interviews. Indicators were determined using qualitative content analysis and literature review. Weighting and ranking identified indicators was performed using fuzzy TOPSIS technique.   

Result: Eleven indicators were identified as follows: management commitment, performance management system, flow of information/communication, involvement culture, error management culture, education, preparedness, flexibility, innovation culture, change management, and human resource management.

Conclusion: Critical sociotechnical organizations especially refinery complexes in order to improve safety management and resilience situation should focus on effective indicators. Monitoring and improving them will increase safety and the resilience level of organization


Maryam Ramin Sabet, Mehran Pourhossein, Monireh Khadem, Fariborz Omidi, Farideh Golbabaei, Seyed Jamaleddin Shahtaheri,
Volume 8, Issue 4 (12-2018)
Abstract

Introduction: Measurement of pesticides in biological matrices is become a serious challenge for researchers due to their very low concentration in different matrices. The aim of this study was to develop a new sample preparation method with high accuracy and validity and short retention time for determination of diazinon.
Material and Method: Dispersive liquid-liquid micro-extraction technique coupled with high performance liquid chromatography equipped with ultra violet detector was developed for trace extraction and determination of diazinon pesticide in human urine samples. One variable at a time method was used to optimize parameters affecting the diazinon extraction. Different parameters such as extraction solvent, disperser solvent, and volume of the extraction solvent, volume of the disperser solvent, centrifugation time and speed, salt addition, and sample pH were studied and optimized.
Result: Findings showed that optimal levels of these variables for diazinon pesticide were 150 μl of carbon tetrachloride as extraction solvent, 1.5 ml of methanol as dispersive solvent, pH of 6, 5 minutes centrifuge time at speed of 4000 rpm , 0% (w/v) salt addition. Correlation coefficient was 0.9965 indicating the linearity of a wide range of concentrations of the toxin. LOD and LOQ was calculated less than 0.7 and 5 µg L-1 respectively. The relative standard deviation for six replicate experiments in intra-day and inter-day at tree selected concentrations (50, 200 and 1000 µg L-1) was less than 4% that indicates the accuracy and precision of the optimized method. Enrichment factor and extraction recovery for diazinon were 245 and 99% respectively.
Conclusion: According to the results, dispersive liquid-liquid micro-extraction procedure was successfully developed for the extraction of diazinon from human urine samples. Compared to other extraction techniques, the proposed procedure had some advantages such as shorter extraction time, better reproducibility, and higher enrichment factor.
Omid Reza Heravizadeh, Monireh Khadem, Ramin Nabizadeh, Seyed Jamaleddin Shahtaheri,
Volume 9, Issue 3 (9-2019)
Abstract

Introduction: Along with the extensive production and use of various pesticides for controlling pests and enhancing the production of agricultural crops, there is a growing concern about the adverse effects of these toxic materials on human health. Therefore, the development of sensitive, selective, and accurate methods for continuous assessment of pesticides concentration in occupational and environmental fields and comparing them with national and international standards is of great importance. This study was aimed at synthesis and application of molecularly imprinted polymer as a selective sorbent for residue determination of two pyrethroid isomers in biological samples.  
Material and Methods: The MIP particles were prepared by a non-covalent approach using permethrin as a template, chloroform as progen solvent, methacrylic acid as functional monomer and ethyleneglycol dimethacrylate as cross-linker, at 55 °C for 18 hours in an oil bath. Field emission scanning electron microscopy was used to investigate the morphology and size of polymer particles. Afterward, the critical parameters, which could affect the recognition properties of synthesized MIP, were investigated and optimized under the selected operational ranges for the highest adsorption and recycling yield in solid-phase extraction of permethrin in biological samples
Results: using precipitation polymerization technique, uniform and spherical particles with the nano-ranged diameter (less than 21.2 nanometers) were obtained. Under the optimized condition, the designed molecularly imprinted solid-phase extraction (MISPE) technique exhibited great potential for the extraction of pesticide isomers in the real sample. More than 93 % of the recovery obtained from spiked urine samples. The linear calibration curve was obtained from 20-120 μg.L-1 (R2=0.99) and the detection limit was less than 6 ppb for both isomers. The presence of interferences had no effect on the selectivity of the method up to 100-fold.
Conclusion: employing the molecular imprinted solid-phase extraction method along with the high-performance liquid chromatography technique resulted in a selective and sensitive approach, suitable for quantitative monitoring of the desired pesticide in complex biological samples.
Somayeh Kamgou, Khosrou Abdi, Monire Khadem, Mahmoud Heidari, Omid Heravizadeh, Ali Daneyali, Seyed Jamaloddin Shahtaheri,
Volume 10, Issue 1 (3-2020)
Abstract

Introduction: Todays, exposure to heavy metals is happened by being produced in various environmental, industrial processes. The production of metals finally results in air pollution as well as contamination in the food chain. There are harmful effects of heavy metals such as cadmium on different organs. Therefore, this study aimed to identify and quantify cadmium in biological samples using DLLME SFOD method.
Materials and Methods: Optimization of the underlying variables played a key role in the process including sample PH, chelator, extractor and disperser solvents, ion concentration, time and rate of centrifugation and extraction time. It was done by employing central composite design (CCD) of the response surface methodology. In the process of optimization, after setting a certain pH, Specific salt concentration and ditizon added to form a complex between the metal and the chelator. A mixture of extraction and dispersant solvents added to the sample. The organic and aqueous phase separations when centrifugation and vortex carried out, the sample vial transferred to a cold ice bath and the organic solvent floated on the aqueous solvent .The organic portion containing the analyte was injected into the analyzer apparatus.
Results. The results showed that variables such as sample PH, complexing solvent, extraction solvent, centrifugation effect and extraction time play an important role in the extraction of cadmium metal ion from biological samples. The optimized method with a minimum detection limit (LOD) of 2 μg / l and a concentration factor (EF) of 50 and a relative recovery (RR) of 1.06.26 used to extract cadmium from urine samples.
Conclusion. According to the pre-test results and the optimization process, they showed that in the three factors of sample PH, salt concentration and extraction solvent volume that play a more effective role in cadmium extraction by DLLME-SFOD method.
Reza Pourbabaki, Monireh Khadem, Sajjad Samiei, Hamid Hasanpour, Seyed Jamaleddin Shahtaheri,
Volume 10, Issue 2 (5-2020)
Abstract

Introduction: Chlorpyrifos is an organophosphorus insecticide that can produce reactive oxygen species, and oxidative stress in the kidney. On the other hand, rosemary extract is an antioxidant playing a protective role against free radicals. Therefore, the aim of this study was to evaluate the oxidative stress in rat kidney due to the exposure to chlorpyrifos and to assess the antioxidant effect of two concentrations of 100 and 200 mg / kg rosemary extract on the nephrotoxicity caused by this pesticide.
Material and method: In the current study, 30 male Wistar Rats, weighing 200-220 g were used. They were randomly divided into five groups and selected as the study groups, each group including six rats  for further comparison. They were as following groupd: Group І: served as control (received dissilated water, i.p) , Group П: the chlorpyrifos exposure group (13.5 mg / kg, i.p.), Group Ш: the group exposed  to rosemary extract (100 mg / kg) by gavage, Group ІV: the exposure group with rosemary 100 mg / kg concentration (by gavage) and after 30 minutes exposure to chlorpyrifos (13.5 mg / kg, i.p.) and Group V: simultaneous exposure of rosemary 200 mg / kg concentration (by gavage) and after 30 minutes exposure to chlorpyrifos (13.5 mg / kg, i.p.). After 2 and 4 weeks, the rats were weighed and killed. A section of kidney tissue was examined for changes of Malondialdehyde (MDA) and Glutathione peroxidase (GPx) and another section was tested for histopathological alterations.
Results: The results showed that chlorpyrifos significantly damaged the kidney tissue and altered the activity of GPx and MDA compared to the control group, as well as it damaged the kidney tissue. Moreover, the simultaneous exposure to chlorpyrifos and rosemary extract with concentration of 100 mg/kg significantly made modifications to the MDA and GPx levels. In addition, with the increasing of rosemary doses from 100 to 200 mg / kg, changes in the levels of MDA and GPx were closer to those of the control group.
Conclusion: The rosemary extract can reduce the oxidative stress caused by chlorpyrifos and, therefore, can be used to treat the poisoning caused by this pesticide.
Saba Kalantary, Monireh Khadem,
Volume 10, Issue 2 (5-2020)
Abstract


Seyedeh Maryam Taheri, Monireh Khadem, Fariborz Omidi, Alirea Sedighi, , Seyed Jamaleddin Shahtaheri,
Volume 11, Issue 1 (3-2021)
Abstract

Introduction: Pesticides are among the broadest chemical compounds used in the world and are also considered as the most dangerous compounds for living organisms. Although pesticides have significant impact on improving agricultural and food products, the processes of their production, formulation, storage, transportation, and marketing as well as the extensive use of these materials lead to occupational exposure, environmental pollution, and the presence of their residues in foodstuffs. Bentazon as a herbicide is considered as one of the most common pesticides used in agriculture and horticulture. Its effects on human health are widespread and of concern. Occupational and environmental exposure assessment of this compound is, therefore, considered necessary by conducting accurate and valid methods. The purpose of the present study was to synthesize a molecular imprinted polymer (MIP) as a specific adsorbent in the preparation process of bentazon for its selective analysis in biological matrices.
Material and Methods: For synthesis, a precipitation polymerization method was used. This method has been used to prepare particle size distribution and shape appropriately. By applying the aforementioned method, nano particle size is obtained within the sub-micron and nano range. So, crushing and sieving of the sorbent is not necessary. The MIP was synthesized with 1: 4: 30 ratio of template molecule (bentazone): functional monomer (methacrylic acid): cross-linking monomer (ethylene glycol di methacrylate), respectively. Due to particle size and high porosity, the sorption and recovery of template compound was performed faster and with higher efficiency. Some variables affecting the efficiency of MIP for sorption and desorption of analyte were investigated and optimized. They included pH of solution, MIP amount (mg), and sonication time (min) in the sorption step and volume of eluent (ml), sonication time (s), and acid percentage in the desorption step.
Results: The optimum levels of factors for the proposed method were pH of solution: 2، sonication time for sorption 7.3 min, polymer amount of 30.814 mg, acid percentage 1.1, and sonication time for desorption 165 s. According to the obtained results, the interfering factors in the matrix have no significant effect on the determination of analyte. The limit of detection (LOD) and relative standard deviation (RSD) of the optimized method were 0.79.ppb and 2.8931 %, respectively.
Conclusion: The results of this study indicated that the proposed method can be used to extract the bentazon herbicide from complex matrices such as urine samples with high efficiency and selectivity.
Monireh Khadem, Elham Kazemi Rad, Mohammad Reza Monazzam Esmaeilpoor, Maryam Mirzaei Hotkani, Sajjad Mozaffari, Amir Abbasi Garmaroudi,
Volume 12, Issue 1 (3-2022)
Abstract

Introduction: One of the most important complications of exposure to noises is changes in the gene expression patterns. Irreversible damage to the inner ear, such as noise-induced hearing loss (NIHL), is caused by tissue damage and changes in the gene expressions in the auditory system. Changes in the GJB2 gene expression pattern lead to autosomal deafness at different loci. The present study aims to evaluate the GJB2 gene expression in cochlear tissue exposed to white noise.
Material and Methods: In this study, ten male Westar rats were divided into two experimental (W1, W2) groups of six rats and a control (normal) group of four rats. Two experimental groups were exposed to constant white noise in the frequency range of 100-20000 Hz and the sound pressure level of 118-120 dB. In order to study the histology and gene expression, after a cochlea biopsy, the histological tests, RNA extraction, cDNA synthesis, and qRT-PCR analysis were performed.
Results: The results showed that the transcript level of GJB2 was significantly decreased in both experimental groups W1 and W2 by 0.02 and 0.12-fold, respectively (p <0.05). Also, the results of the histological study showed that cochlear tissue was more seriously damaged in the W1 group than W2.
Conclusion: It can be concluded that a significant reduction in the GJB2 gene expression and irrevocable damage to auditory nerve ganglion and Reissner membrane (vestibular membrane) caused changes in the gene expression patterns in cochlear tissue and developed the risk of non-syndromic sensorineural hearing.
Ali Mohammad Mossadeghrad, Alireza Sadraei, Mohammad Reza Monazzam Ismailpour, Seyed Jamaleddin Shahtaheri, Seyed Abolfazl Zakerian, Adel Mazloumi, Monireh Khadem, Mahya Abbasi, Ali Karimi, Farideh Golbabaei,
Volume 12, Issue 4 (12-2022)
Abstract

Introduction: Universities play a key role in creating a knowledge-based society and its sustainable development. Strategic planning by strategically analyses internal and external environments of the organization, forecast its future, identifying its strategic direction, and strengthening organizational structures, processes, and outcomes, creates and sustains competitive advantages. This study aimed to formulate a strategic plan for the Occupational Health Engineering (OHE) department of School of Public Health (SPH) at Tehran University of Medical Sciences (TUMS).
Material and Methods: In this participatory action research, a strategic planning committee was formed. The strategic planning committee used the strength, weakness, opportunity and threat (SWOT) matrix to evaluate the internal and external environments of the OHE department. Then, the mission, vision, values, goals and objectives of the OHE department were defined. Finally, the operational plan including actions to achieve the goals and objectives were formulated.
Results: Experienced professors and staff, specialized laboratories, professional journals, and high ranked postgraduate students were the most important strengths; and theoretical and non-practical courses, lack of educational protocols, poor communication with industries, lack of resources, and low motivation of employees were some of the weaknesses of the OHE department.  The support of senior managers of TUMS, industry liaison council at school and university, facilities of the university faculties, comprehensive research laboratories of the university, capacities of the private sector and increasing the demand for research in the industry were the opportunities. High inflation, political sanctions, the absence of consulting engineering companies and the uncertainty of research priorities of industries were important threats to the OHE department. Therefore, the OHE department is in a conservative strategic position. The strategic direction of the department, including the mission, vision, values and goals, until 2025 was determined. Improving the structures, working processes and performance of the occupational health department were determined as objectives and 81 actions were formulated to achieve these objectives.
Conclusion: The educational departments, schools and universities must have a strategic plan for progress. The strategic plan of the occupational health department of TUMS was formulated in line with the four-year plan of the university and coordinated with the operational plans of the educational, health and research deputies of TUMS and school of public Health. Proper implementation of this comprehensive and evidence-based strategic plan will improve the performance of the occupational health department.
Mahdi Alinia Ahandani, Saba Kalantary, Monireh Khadem, Fatemeh Jafari, Kamal Azam, Farideh Golbabaei,
Volume 13, Issue 4 (12-2023)
Abstract

Introduction: VOCs are harmful air pollutants that must be detected, monitored and eliminated. Adsorber tubes are standard tools for this task, specifically activated carbon tubes with high adsorption and selectivity. This research aims to compare the structural and functional characteristics of domestically produced activated carbon tubes with the conventional commercial ones for sampling toluene, a volatile organic compound.
Material and Methods: The characteristics of each adsorbent, such as structure, morphology, porosity, and element composition, were examined by SEM photography, BET testing, and EDAX analysis. The central composite design (CCD) method was employed to investigate the adsorption properties of the adsorbents. The input concentration and readsorption time of the samples were the variables considered in this study. Additionally, a field phase of personal air sampling was performed to evaluate the effectiveness of adsorbent tubes.
Results: SEM and BET analyses indicated that the porous structure of domestic activated carbon was comparable to the model produced by SKC. EDAX analysis detected a minor impurity (1%) in the domestic activated carbon adsorbent. The adsorption performance was significantly influenced by the variations in readsorption time and pollutant input concentration. The accuracy and precision of the performance of the domestic adsorbent tube were obtained as 90.77% and 91.76%. The field phase results demonstrated that the amount of pollutant adsorbed in the SKC-activated charcoal adsorber did not differ significantly during 0 to 30 days. However, the domestic adsorber showed a significant difference in the same period. The overall performance of the two adsorbers did not exhibit a significant difference between 0 and 30 days.
Conclusion: Despite minor structural differences, the adsorption efficiency of toluene by domestic adsorbent tubes in sampling high concentrations is very similar to its commercial type. However, it is not recommended for use in low-concentration environments (10 ppm and less).
Ali Mohammad Mosadeghrad, Mohammad Reza Monazzam Ismailpour, Seyed Jamaleddin Shahtaheri, Seyed Abolfazl Zakerian, Adel Mazloumi, Monireh Khadem, Mahya Abbasi, Ali Karimi, Hasan Karimi, Farideh Golbabaei,
Volume 14, Issue 1 (3-2024)
Abstract

Introduction: The purpose of occupational health is to maintain and improve the health of employees and improve their physical, mental and social well-being through the prevention, control and elimination of occupational hazards. It is necessary to integrate educational, research and health service activities to prevent and control potential occupational health hazards in the community. This study aimed to develop a Joint Comprehensive Plan Of Action (JCPOA) for occupational health at Tehran University of Medical Sciences (TUMS).
Material and Methods: In this participatory action research, a strategic planning committee was established, whose members were professors of the occupational health department in the school of public health and managers of the occupational health department in the health deputy of TUMS. The strategic planning committee carried out a strategic evaluation of the internal and external environments of both occupational health deprtments of TUMS and identified the strengths, weaknesses, opportunities and threats. Then, the strategic direction of JCPOA including the vision, mission, values, goals and objectives was determined. Also, the strategies and actions to achieve the goals and objectives were identified. Finally, the action plan to achieve these objectives was developed.
Results: This applied research led to the strategic evaluation of the internal and external environments of the occupational health depratment of the School of Public Health and the occupational health depratment of the Health deputy of TUMS, determining the strategic direction, and finally, developing an action plan to achieve the goals and objectives.
Conclusion: The JCPOA for occupational health was developed using a collaborative and systemic approach. The proper implementation of this plan can lead to the improvement of occupational health indicators in the community. Cooperation between university and industry is necessary for the sustainable development of society.

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