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Background and purpose: Air pollution is one of the most important environmental factors threatening human health that cause short and long term health effects and various diseases. The present study aimed at investigating and quantifying the health consequences associated with exposure to O3, NO2, and SO2 in ambient air in Tehran, 2014, using the air quality (Air Q) model.

Materials and methods: A descriptive–analytic study was performed in which hourly data of pollutants were taken from Tehran environmental protection agency and Air Quality Control Company. Data was validated according to the WHO guidelines. Statistical parameters were calculated for quantifying health effects. Then, processed data was converted for Air Q model.  

Results: The highest cumulative cases of mortality was due to NO₂ (n= 1274, attributable proportion= 2.51). Also, cumulative cases of hospital admission due to chronic obstructive pulmonary disease were attributed to O₃ (n= 240 cases, attributable proportion= 2.54). The number of heart attack cases due to SO₂ was 225.

Conclusion: According to the growing trend of air pollution, resultant mortality rate, and adverse effects more efficient solutions are required to control and reduce air pollution in Tehran.

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Background and purpose: Nitrobenzene (NB) as the main material of synthetic fuels, cleaners, rubber and explosives is discharged into the environment and groundwater in large-scale. This compound is considered as a persistent organic pollutant with high toxicity and stable chemical structure which can cause serious risks for human health and ecosystem even in low concentrations. Therefore, the aim of present study was to synthesize polyaniline/zero-valent iron composite nano-fiber (CNFs) and its ability in degradation of nitrobenzene from aqueous solution.

Materials and methods: Characterization of CNFs was determined using scanning electron microscopy, transmission electron microscopy, X-ray diffraction and vibrating sample magnetometer. The effect of operational parameters such as pH, NB concentration and nanocomposite dosage on nitrobenzene degradation were analyzed by response surface methodology. Box Behnken model was used to investigate the interaction among variables. Analysis of variance was considered as statistical method for responses analyzes.

Results: ANOVA test showed a significant relationship between statistical model and test data. The observations also revealed that the distribution of residuals were normal and parameters i.e. pH, NB concentration, nanocamposite dosage and interaction of nano-composite and NB concentration had significant effect on removal of NB. The degradation efficiency was over 98% in optimized conditions (pH=2, NB concentration= 40 mg/l, and nanocomposite dosage= 0.88 g/l) that was achieved in 45 minutes. Limit of Detection (LOD) and Limit of Quantification (LOQ) were calculated as 1.5 and 5 mg/l, respectively.

Conclusion: According to the results, polyaniline nanofiber composite/zero-valent iron has a good efficiency in NB degradation. NB kinetic studies showed that the NB degradation process by nanocomposite followed the one order kinetic model. In addition, the nano-composite separation is simple due to its magnetism properties that it can improve its application.

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 Background and purpose: The Coronavirus Disease 2019 (COVID-19) was first observed in December 2019 and caused a global pandemic. The aim of this study was to evaluate the clinical features and paraclinical findings in patients who died of COVID-19 in Sari Imam Khomeini Hospital, February 2020- May 2020.
Materials and methods: A cross-sectional descriptive and retrospective study was done by reviewing the medical records of 149 patients who died of Covid-19 whose diagnosis was confirmed by chest CT scan or PCR-RT. Independent sample t test was used to compare quantitative variables and Chi-square test was used for analyzing qualitative variables.
Results: The mean age of death from Covid-19 was 63.36±15.26 years and 58.1% were male. The most common clinical complaints were cough, fever, and dyspnea. The most common manifestation of chest CT scan was bilateral involvement. Among the dead cases of COVID-19, 13.5% had myocarditis and 4.7% developed respiratory complications (such as pneumothorax). According to findings, 54.1% died of cardiac arrest and 44.6% died due to respiratory arrest.
Conclusion: Many ambiguities of SARS-CoV-2 still remain that require extensive studies and research in various aspects. Evaluation of demographic, radiological, clinical complications, and laboratory features can help physicians in finding ways to reduce mortality, perform more effective treatments, and use predictive tools.