ABSTRACT
Non-thermal dielectric barrier discharge (DBD) plasma has received great attention for degradation of persistent organic pollutants such as p-nitrophenol (PNP). However, the feasibility of the DBD implementation is not clear due to its high energy consumption and relatively low degradation efficiency. In this research, a novel strategy was suggested based on re-circulation of the generated O3 in the DBD system to enhance the PNP degradation efficiency and energy yield. The potential mechanism and possible pathway of PNP degradation were studied by EPR, ESR, DFT and GS-MS analytical tests. According to the results, the PNP degradation efficiency and energy yield increased from 57.4% to 94.4% and from 0.52 to 1.18 g kW-1h-1, respectively through ozone circulation into the DBD reactor. This was due to the more release of long-lived and short-lived reactive species (ROS) in the DBD-O3 system by the O3 circulation. The variations in pH (4-10), initial concentration (50-90 mg L-1), and the presence of co-existing substances in the water matrix had minimal impact on the DBD-O3 system, in comparison to the conventional system. The biological toxicity evaluation revealed that the hybrid DBD-O3 system transform PNP to less toxic intermediates. This study proposes a promising strategy to improve the utilization of DBD for the degradation of PNP.
ABSTRACT
Given the increase in the incidence of breast cancer during the past decades, several studies have investigated the effects of variables on breast cancer, especially obesity. This systematic review and meta-analysis aims to evaluate any effects of obesity on breast cancer risk in women, before and after menopause, and in different continents.All forms of relevant literature examining any association between obesity and breast cancer, including cohort, case-control, and cross-sectional studies, were identified in the PubMed, Scopus, EMBASE, and Web of Science databases from January 1, 1990 until January 13, 2023. Body mass index (BMI) > 30 was used to indicate obesity. Every type of breast cancer was examined as outcome factors. The quality of the papers was evaluated using the Newcastle-Ottawa scale checklist. The Egger and Begg test was used to evaluate publication bias. To assess any extra impact of each research on the final measurement, a sensitivity analysis was carried out.One hundred and two studies were included in this meta-analysis. Respectively, 48 and 67 studies reported associations between obesity and breast cancer in pre and post menopausal women. Combining all studies, the pooled OR of the association between obesity and breast cancer in pre-menopausal women was OR = 0.93 CI: (0.85-1.1), (I2 = 65.4%), and for post-menopausal woman, OR = 1.26 CI: (1.19-1.34), (I2 = 90.5%).Obesity has a protective role in breast cancer among pre-menopausal women, but this relationship is statistically significant only in European women. The chance of developing breast cancer increases in post-menopausal women who are obese. This relationship is significant among Asian, North American, African and European women.
