RESUMEN
The presence of lead as an environmental pollutant is widespread. However, safe and effective treatments for the resulting intestinal and liver damage from high levels of lead exposure remain limited. The study aimed to investigate the protective effects of dietary fiber and polyphenols in whole grain wheat flour on lead-induced mice. The results indicated that the daily intake of 12 mg of polyphenols, 0.5 g of dietary fiber, and their combination effectively reduced blood and liver lead accumulation by approximately 50 % in mice exposed to lead, while also mitigating lead-induced oxidative stress though a reduction in malondialdehyde levels and an enhancement in antioxidant enzyme activities including superoxide dismutase, catalase, and glutathione peroxidase. Furthermore, all three treatments enhanced cytokine secretion with the combined treatment exhibiting the highest efficacy. Specifically, the combination treatment decreased tumor necrosis factor-α and interleukin 1ß by 56.78 %, 47.86 % in intestinal tissue while increasing increased interleukin 4 and interleukin 10 by 81.84 %, 145.14 %. Additionally, it promoted the expression of tight junction proteins like Zonula occludens-1, Occludin and Claudin-1. The study presented a potential strategy for alleviating liver and intestinal tract damage from high-dose lead exposure.
RESUMEN
The direct oxidative esterification of benzaldehydes and benzyl alcohols to high value-added aromatic esters under mild and green reaction conditions is significant in the fine chemical industry. The accurate design of catalysts with high catalytic performance is crucial for this process. Herein, 2,4,6-trimethylpyridine, benzoic anhydride, and terephthalaldehyde were used to prepare a covalent organic framework (COF) material, which was then used as a template to construct a mesoporous CeO2-supported Au nanoparticles catalyst. The obtained Au@CeO2 catalyst was thoroughly characterized, and it possessed a mesoporous structure with a high surface area. Meanwhile, the as-prepared Au@CeO2 exhibited excellent catalytic performance in the oxidative esterification of benzaldehydes and benzyl alcohols with methanol, affording the corresponding aromatic esters under mild and green reaction conditions. Furthermore, the Au@CeO2 catalyst could also be recycled. Therefore, this study provides a green and sustainable pathway for the synthesis of high-value-added esters through a direct oxidative esterification strategy.
RESUMEN
As China's political and economic centre, the Beijing-Tianjin-Hebei (BTH) urban agglomeration experiences serious environmental challenges on particulate matter (PM) concentration, which results in fundamental or irreparable damages in various socioeconomic aspects. This study investigates the seasonal and spatial distribution characteristics of PM2.5 concentration in the BTH urban agglomeration and their critical impact factors. Spatial interpolation are used to analyse the real-time monitoring of PM2.5 data in BTH from December 2013 to May 2017, and partial least squares regression is applied to investigate the latest data of potential polluting variables in 2015. Several important findings are obtained: (1) Notable differences exist amongst PM2.5 concentrations in different seasons; January (133.10 mg/m3) and December (120.19 mg/m3) are the most polluted months, whereas July (38.76 mg/m3) and August (41.31 mg/m3) are the least polluted months. PM2.5 concentration shows a periodic U-shaped variation pattern with high pollution levels in autumn and winter and low levels in spring and summer. (2) In terms of spatial distribution characteristics, the most highly polluted areas are located south and east of the BTH urban agglomeration, and PM2.5 concentration is significantly low in the north. (3) Empirical results demonstrate that the deterioration of PM2.5 concentration in 2015 is closely related to a set of critical impact factors, including population density, urbanisation rate, road freight volume, secondary industry gross domestic product, overall energy consumption and industrial pollutants, such as steel production and volume of sulphur dioxide emission, which are ranked in terms of their contributing powers. The findings provide a basis for the causes and conditions of PM2.5 pollution in the BTH regions. Viable policy recommendations are provided for effective air pollution treatment.
