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Background & Aim: Due to the side effects of chemical and synthetic preservatives, consumers have recently become more eager to use foods containing natural preservatives from plants, animals and microbial sources. In the present study, biochemical composition and antibacterial effects (MIC) of Mentha longifolia L. essential oil against Staphylococcus aureus have been evaluated. Methods: In this experimental study, the biochemical composition and antibacterial prosperities of this essential oil was determined by the Gas chromatography/ mass spectrophotometer (GC/MS) and micro dilution method respectively. The morphological and membrane changes of the bacterial cell under the effect of this essential oil were evaluated by transmission electron microscopy. The collected data was analyzed by the SPSS software using ANOVA. Results: The chemical analysis of the essential oil by Gas chromatography/ mass spectrophotometer (GC/MS) revealed the presence of 22 substances (95.30%), mainly including Pulegon (31.54%), 1,8 Cineol (15.89%), Menthoforan (11.8%) and Cis- Isopulegon (9.74%). Minimum inhibitory concentration of the essential oil determined under different temperature and pH values showed to be in the range of 75-1200 µg/ ml. Conclusion: The MIC results and membrane cell damage observed in the electron microscopy evaluation indicated that this essential oil have a high antibacterial activity. Therefore, this essential oil can be combined with other agents for the preservation of foods against pathogenic and toxigenic microorganisms.

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Background & aim: Computed tomography (CT) scan of the chest is a common tool for imaging in pneumonia that is relatively easy and quick to detect. The aim of this study was to determine and evaluate the different characteristics of CT scan of patients with COVID-19 in Ahvaz hospitals.
 
Methods: The present survey was a descriptive-analytical retrospective study conducted in 2020. The statistical population included all patients referred to Corona Specialized Hospital who had positive COVID-19 and RT-PCR test and are hospitalized for treatment. Of these, 40 (22 men and 18 women) were included in the study. Patients who refused a CT scan of the chest or hospitalization, any coronary syndrome, any aortic or pulmonary embolism, or who were reluctant to participate were excluded from the study. All scans were reviewed and reported by a radiologist. The collected data were analyzed using Chi-square and t-test.
 
Results: Image analysis indicated that multiple involvement was observed in 37 cases (92.5%). Frosted glass opacity (GGO) was more observed in the posterior sections (p <0.001). Consolidation was more common in the posterior sections, with the posterior section of the right lower lobe (RLL) being more involved (p <0.001). Crazy paving was more common in part 6 of the right middle lobe (15%) (p <0.001). Halo and reversed halo were observed in only 1 patient (2.5) and 2 (5%), respectively.
 
Conclusion: In conclusion, a typical CT-Scan sign obtained for patients with COVID-19 in Ahvaz, Iran, was multipolar bilateral sub pleural ground-glass opacity (most seen in RLL posterior segment) followed by consolidation and crazy paving.