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The seasonal distribution of SARS-CoV-2 might be affected by air pollution. To test the hypothesis, epidemic determinants, namely, shape, timing (Peak and Trough) and size (Peak to Trough Ratio and Excess Risk) of seasonal distribution of the outbreak were compared before and after adjusting for air pollutants in a distributed lag nonlinear model. We controlled for one-lagged outcome and meteorological parameters in the model. We also evaluated interaction effect between air pollutants and season using stratification method. The epidemic determinants were changed after adjusting for PM2.5 and O3 in the model, suggesting the existence of their association with the seasonal distribution of the outbreak. The Excess Risk of season (i.e., the proportion of confirmed Covid-19 cases that were attributed to season; AF) was increased as %4 (%95 CI − 29, 38) after adjusting for PM2.5. Adjusting for O3 in the model resulted in % 1 (%95 CI − 36, 34) decrease in the index. NO, NO2 and SO2 had no association with the seasonal distribution, though the interaction analysis revealed that association of NO2 and SO2 with Covid-19 confirmed cases were significantly higher in fall than winter and spring, respectively. Totally, PM2.5 has negatively associated with the seasonal distribution of the outbreak while O3 has positively associated in the region under study. Although some reasons such as wearing mask and oxidative effect might go before the negative and positive associations, but our results suggests that any association and causation between air pollution and Covid-19 should be carefully interpreted. [ABSTRACT FROM AUTHOR]

The aims of this study were to i) assess the relationship between COVID-19 cases with PM10 concentration and ii) investigation premature deaths due to cardiovascular (M-CVD) and respiratory (M-RD) diseases in three classification levels (PM10<50µg m−3 in normal days, 50–200 µg m−3 in dusty days, and >200 µg m−3 in MED storm), by using daily averages of PM10 concentrations. The number of M-CVD and M-RD were estimated by concentration-response model, per 105 people during 2017 to 2021. The results showed that 187, 183, 163, 215, and 206 days were observed with the PM10 concentrations lower than 50 µg m−3 during 2017 to 2021, and 178, 180, 200, 150, and 149 days were subtotal with exceeding PM10 from the WHO guideline (50 µg m−3), respectively. A positive correlation (r2=0.33, p < 0.05) was found to be between the number of COVID-19 cases and PM10 mean concentrations (r = 0.589, p = 0.046). Our findings showed that the highest M-CVD and M-RD were among exposed people at dusty days (50 < PM10≤ 200 μg m−3) in 2019. The total M-CVD and M-RD from 2017 to 2021 were 11.78 and 12.2, 18.25 and 17.4, 22.29 and 23.78, 10.33 and 7.6, 10.37 and 9.95 per 105 people, respectively which 31.48% of health effects were related to PM10 concentrations more than 200 μg m−3. [ABSTRACT FROM AUTHOR]

This paper introduces a novel and minimized sample preparation technique based on hollow fiber-protected liquid-phase microextraction that can be used in joint with gas chromatography-mass spectrometry (GC-MS) detection to extract three organochlorine pesticides-Endrin, Chlordane, and Dieldrin-from rice samples. To that end, a single-walled carbon nanotube (SWCNT) and a proper ionic liquid (IL) were ultrasonically dispersed and injected into the lumen of hollow fiber as the extraction phase for preconcentrating and extracting the target analytes from the rice samples. The effects of the type of nanoparticles, ILs, and desorption solvent on the efficiency of extracting the analytes were investigated based on the one-factor-at-a-time (OFAT) approach. In addition, other parameters influencing the extraction procedure were optimized using an experimental design that decreased the number of experiments, reagent consumption, and costs. Under optimized conditions, the limits of detection and quantification in determining mentioned pesticides varied between 0.019-0.029 and 0.064-0.098 ng mL -1 , respectively. The calibration graphs to measure Endrin, Chlordane, and Dieldrin were linear over the concentration range of 0.064-13.2, 0.098-16.7, and 0.092-11.4 ng mL -1 , respectively. The relative standard deviations for inter-day and intra-day analysis were below 7.06 and 4.75% for the triplicate determination of three organochlorine pesticides. Besides, the relative recoveries and standard deviations of Endrin, Chlordane, and Dieldrin for analyzing several Iranian rice samples were between 86.0-92.9% and 4.5-5.8%, respectively. The results were compared with other similar works in literature, proving that the proposed method is efficient and useful for routine monitoring of organochlorine compounds in food samples., (© 2023. The Author(s), under exclusive licence to Springer Nature B.V.)

Astragalus is a well-known genus in Leguminosae family that represented more than 800 species growing in Iran. Nevertheless, there are a few reports on Astragalus plants endemic to Iran. The roots of Astragalus plants are rich in saponins, flavonoids and polysaccharides that possess various pharmacological activities. In the present study, chemical components, antioxidant and antibacterial activity of Astragalus chrysostachys Boiss. roots were evaluated. For determination of phytochemicals in Astragalus chrysostachys Boiss. roots, total hydroalcoholic extract was fractionated with ethyl acetate and n-butanol. Ethyl acetate extract as a flavonoid rich extract was analyzed using vacuum liquid chromatography and preparative TLC and consequently a major flavonoid was isolated. The structure of the obtained compound was elucidated with 1D and 2D NMR experiments. Additionally, the essential oil of the roots was analyzed by GC-MS. Antioxidant activity of all extracts was evaluated by different assays. Moreover, antibacterial activities of the extracts were also investigated against 2 Gram-positive and 2 Gram-negative bacteria using Micro-dilution Broth method. Apigenin-6, 8-di-C-glucoside was detected in ethyl acetate extract for the first time in genus Astragalus. In addition, m-tolualdehyde, acetophenone, croweac in were found to be characteristics of the volatile oil of roots. Ethyl acetate extracts revealed notable antioxidant activity in DPPH scavenging assay with IC50 value of 14.6 µg/mL. Evaluation of antibacterial activity on the tested extracts showed mild activity against Gram-positive bacteria. Since there have been no reports on Astragalus chrysostachys Boiss. to date, the present data might be promising for application of this plant derivatives in phytotherapeutic practice. [ABSTRACT FROM AUTHOR]

Experimental studies on the retention of cadmium (Cd2+), copper (Cu2+), nickel (Ni2+), and lead (Pb2+) by bentonite samples from Iran were conducted using single- and multiple-component solutions. Based on the sorption capacity of bentonite the following order was obtained for single- and multiple-component solutions: Pb2+ > Cd2+ > Ni2+ > Cu2+. The maximum adsorption capacities of bentonite with metals in single- and multiple-component solutions were 29.5%, 22.5%, 19.2%, and 17.1% and 13.5%, 13.4%, 12.1%, and 9.1% for Pb2+, Cd2+, Ni2+, and Cu2+, respectively. Desorption isotherms of Cd2+, Cu2+, Ni2+, and Pb2+deviated significantly from the sorption isotherms, thereby indicating irreversible or very slowly reversible sorption. Finally, soil solution saturation indices and metal speciation were assessed using the Visual MINTEQ 2.6 program and the probability of mineral precipitation was supported by scanning electron microscopy. [ABSTRACT FROM AUTHOR]