Outline of changes in cortisol and melatonin circadian rhythms in the security guards of Shiraz University of Medical Sciences

Background: According to the literature, a large number of people working in industries and service providing personnel, such as firefighters, physicians, and nurses are shift workers. The spread of shift working in industrial societies and the incidence of the problems resulting from shift working have caused the researchers to conduct studies on this issue. The present study also aimed to investigate melatonin and cortisol circadian rhythms in the security guards of Shiraz University of Medical Sciences, Shiraz, Iran. Methods: The present study was conducted on 20 security guards of Shiraz University of Medical Sciences. In order to collect the study data, blood samples were taken from the study subjects in different times of the day (1, 4, 7, 10, 13, 16, 19, and 22) and cortisol and melatonin levels were determined using the radioimmunoassay and enzyme immunoassay techniques, respectively. Results: The results showed that as the intensity of light increased at night, the plasma cortisol level increased, as well. Besides, no statistically significant difference was found between the plasma cortisol levels in natural light and 4500-lux light. On the other hand, a significant difference was observed between the plasma cortisol levels in natural light and 9000-lux light as well as 4500- and 9000-lux lights. The study findings also showed that as the intensity of light increased at night, the plasma melatonin level decreased. In addition, a statistically significant difference was found between the plasma melatonin levels in natural light and 4500-lux light. Nevertheless, no significant difference was observed between the plasma melatonin levels in the natural light and 9000-lux light as well as 4500- and 9000-lux lights. Conclusions: The present study aimed to investigate the subsequences of shift working in the security guards of Shiraz University of Medical Sciences and showed that occupational exposure to bright light could affect some biological markers, such as melatonin and cortisol secretion

Outline of changes in cortisol and melatonin circadian rhythms in the security guards of Shiraz University of Medical Sciences

Background: According to the literature, a large number of people working in industries and service providing personnel, such as firefighters, physicians, and nurses are shift workers. The spread of shift working in industrial societies and the incidence of the problems resulting from shift working have caused the researchers to conduct studies on this issue. The present study also aimed to investigate melatonin and cortisol circadian rhythms in the security guards of Shiraz University of Medical Sciences, Shiraz, Iran. Methods: The present study was conducted on 20 security guards of Shiraz University of Medical Sciences. In order to collect the study data, blood samples were taken from the study subjects in different times of the day (1, 4, 7, 10, 13, 16, 19, and 22) and cortisol and melatonin levels were determined using the radioimmunoassay and enzyme immunoassay techniques, respectively. Results: The results showed that as the intensity of light increased at night, the plasma cortisol level increased, as well. Besides, no statistically significant difference was found between the plasma cortisol levels in natural light and 4500-lux light. On the other hand, a significant difference was observed between the plasma cortisol levels in natural light and 9000-lux light as well as 4500- and 9000-lux lights. The study findings also showed that as the intensity of light increased at night, the plasma melatonin level decreased. In addition, a statistically significant difference was found between the plasma melatonin levels in natural light and 4500-lux light. Nevertheless, no significant difference was observed between the plasma melatonin levels in the natural light and 9000-lux light as well as 4500- and 9000-lux lights. Conclusions: The present study aimed to investigate the subsequences of shift working in the security guards of Shiraz University of Medical Sciences and showed that occupational exposure to bright light could affect some biological markers, such as melatonin and cortisol secretion

Comparison the efficiency of Fenton and Photo–fenton processes for the removal of Reactive red 198 Dye from the aqueous solution

The textile industry produces a large amount of polluted effluents discharged into the environment. Therefore, this research was carried out to compare the efficiency of removal of Reactive red 198 (RR–198) dye by fenton and photo–fenton processes and determine the optimal conditions for maximum removal. This study was conducted on a laboratory scale. The effect of influential parameters, including pH (3–9), Fe(II) concentration (10–200mg/L), H2O2 concentration (25–150mg/L), dye concentration (50–200mg/L) and reaction time (15–90min.) on dye removal was investigated and the optimal conditions were determined according to the maximum dye removal efficiency. The results indicated that the dye removal rate increased as the pH and Fe(II) concentration decreased. The optimal conditions for RR–198 removals from the aqueous solution are pH of 3, Fe (II) concentration of 10mg/L, H2O2 concentration of 50mg/L, the initial dye concentration of 50mg/L, and the reaction time of 15min.. The maximum dye removal efficiency under optimal conditions was 98.82%. The results of this study revealed that the photo–fenton process was superior to the removal of dye compared to fenton process

Study of the Bioremediation of Atrazine under Variable Carbon and Nitrogen Sources by Mixed Bacterial Consortium Isolated from Corn Field Soil in Fars Province of Iran

Atrazine herbicide that is widely used in corn production is frequently detected in water resources. The main objectives of this research were focused on assessing the effects of carbon and nitrogen sources on atrazine biodegradation by mixed bacterial consortium and by evaluating the feasibility of using mixed bacterial consortium in soil culture. Shiraz corn field soil with a long history of atrazine application has been explored for their potential of atrazine biodegradation. The influence of different carbon compounds and the effect of nitrogen sources and a different pH (5.5–8.5) on atrazine removal efficiency by mixed bacterial consortium in liquid culture were investigated. Sodium citrate and sucrose had the highest atrazine biodegradation rate (87.22%) among different carbon sources. Atrazine biodegradation rate decreased more quickly by the addition of urea (26.76%) compared to ammonium nitrate. Based on the data obtained in this study, pH of 7.0 is optimum for atrazine biodegradation. After 30 days of incubation, the percent of atrazine reduction rates were significantly enhanced in the inoculated soils (60.5%) as compared to uninoculated control soils (12%) at the soil moisture content of 25%. In conclusion, bioaugmentation of soil with mixed bacterial consortium may enhance the rate of atrazine degradation in a highly polluted soil

Decolorization of Direct Red 81 in Aqueous Solutions by Fenton Oxidation Process: Effect of System Parameters

Dye industries and textile are among the most water-consuming industries, which severely disturb the aquatic life. Therefore, the aim of this study was to determine the feasibility of Fenton process in removing Direct Red 81 dye from aqueous solutions and the optimal conditions for maximum removal. This research was conducted in a laboratory-scale using a one-litre photochemical reactor. The effect of the influential parameters, including pH (3–9), Fe (II) concentration (10–150mg/L), H2O2 concentration (20–150mg/L), initial dye concentration (25–150mg/L), and reaction time (15–120min) on the dye removal was investigated and the optimal conditions were determined according to maximum dye removal efficiency The results showed that the dye removal rate increased as the pH and Fe(II) concentration decreased and as the initial dye concentration and time increased. The optimal condition was at pH=3, Fe (II)=10mg/L, H2O2=50mg/L, initial dye concentration=100mg/L, and reaction time= 45 minutes. Although the maximum removal efficiency (98.29%) was obtained at the reaction time of 120 minutes, 45 min was the appropriate reaction time considering the cost-effectiveness. Our results suggest that the Fenton process is a reliable and efficient method with more than 95% efficiency for decolourization of DR-81 dye and many industrial wastewaters