Socio-demographical Profile of 7285 SARS-Cov-2 Positive Early Cases; Comparison with National Four Epidemic Waves.

Background: Objectives were to investigate aspects of the COVID-19 epidemics via testing the individuals who were referred to Aramesh Medical Laboratory in Tehran and to integrate the molecular results with epidemiological data since the beginning of the epidemic. Methods: In this cross-sectional Study 77528 outpatients were referred to Aramesh Medical laboratory by physicians for the diagnosis of SARS-CoV-2 infection between March 2019 and May 2021. Viral acid nucleic extracted from nasal and throat specimens and subsequently amplified using Reverse Transcriptase Real-Time PCR. Laboratory data including Ct values compared with epidemic peaks of COVID-19 countrywide. Statistical Analysis was done by SPSS 21 Software. Results: 14312 (18.46%) tested positive.36.5% of the positive cases were in the 30 to 39 years old age group. The positive result rate was significantly different based on months, ranging from 6% to 28%, compatible with four recognized epidemic peaks encompassing the end of March through the first week of April (first epidemic peak), from June to July 2020 (second epidemic peak), October until mid of November 2020 (third epidemic wave) followed by the end of April to May 2021 (until the end period of study, in the middle of 4th peak). In 37.8% of cases, the Ct value was between 21 and 28. Two separate trends were seen for Ct ≤ 25 and Ct ≤ 20 for the first and fourth epidemic peaks, respectively. There was an association between the number of total monthly positive results and total deaths in the country, especially with the second to third peaks (in the course of summer 2020) and fourth epidemic peak. Conclusion: It might be useful to consider laboratory admission rates as an indicator for changes in the epidemic level in the country to continue the SARS-CoV-2 surveillance in accordance with public decision-makers.

Duckweed Potential for the Phytoremediation of Linear Alkylbenzene Sulfonate (LAS): Identification of Some Intermediate Biodegradation Products and Evaluation of Antioxidant System.

Duckweed (Lemna minor L.) has a high potential for wastewater treatment. Here, its capability for bioremoval of linear alkylbenzene sulfonate (LAS) as one of the primary contaminants of water resources was evaluated. The effect of some operational parameters on surfactant removal efficiency was determined. Also, the impact of LAS on several physiological responses of Lemna was investigated. LAS remediation efficiency of L. minor was elevated with increasing LAS concentration, duckweed weight, and temperature. Furthermore, the optimal pH for removal was 7-8.5. The benzenesulfonate ring and five homologs of sulfophenyl carboxylate were identified as intermediates in the LAS degradation pathway. A decrease in relative growth rate and pigment contents was observed by increasing LAS concentration. In contrast, an increase in hydrogen peroxide content and electrolyte leakage indicated oxidative stress by LAS. Induction of enzymatic/non-enzymatic antioxidants was observed during the surfactant remediation process, indicating their role in overcoming free radicals generated under surfactant stress.

Phytoremediation potential of Azolla filiculoides for sodium dodecyl benzene sulfonate (SDBS) surfactant considering some physiological responses, effects of operational parameters and biodegradation of surfactant.

In this study, phytoremediation potential of the Azolla filiculoides Lam. was examined for sodium dodecyl benzene sulfonate (SDBS) anionic surfactant. Furthermore, the effect of surfactant treatment on some physiological characteristics of Azolla was studied. The surfactant bioremoval efficiency was studied under variable conditions including treatment time, initial surfactant concentration, Azolla fresh weight, temperature, and pH. Results showed that surfactant removal efficiency of A. filiculoides was significantly enhanced with increasing of temperature, initial surfactant concentration, and amount of Azolla. SDBS led to a reduction in growth rate and total chlorophyll content, but effect index of Azolla increased by higher concentrations of surfactant. In contrast, antioxidant enzymes activities including polyphenol oxidase, ascorbate peroxidase, catalase, and peroxidase, as well as nonenzymatic antioxidants such as total carotenoids and anthocyanin contents significantly increased probably due to the ability of plant to overcome oxidative stress induced by SDBS. An increase in antioxidant activity based on 2, 2-diphenyl-1-picrylhydrazil (DPPH) confirmed this fact. An increase in the amount of hydrogen peroxide and reduction in membrane stability index indicated the induction of oxidative stress. As a result of SDBS biodegradation, 6 homologs of sulfophenyl carboxylates (SPCs) including C2 to C7-SPC and benzenesulfonate ring were identified by liquid chromatography-mass spectroscopy (LC-MS) analysis.