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Abstract Background: The dibutyl phthalate (DBP) is a member of the phthalate family and is widely used as a plasticizer in daily life and production. However, the influence of DBP on the vascular developmental remains unclear. Methods: In this study, we used zebrafish as a model organism to investigate the effects of DBP on vascular development in vivo. Death curves of zebrafish at different concentrations of DBP exposure and different times incubation were made firstly. Zebrafish embryos after fertilization for 5.5 h were exposed to different concentrations of DBP solution (0, 0.4, 0.8, 1.2 mg/L), the body length, yolk sac absorption area, mortality and heart rate of zebrafish were measured, and the number and area of sprouting of ventral vessels were quantified by transgenic fish system. Reactive oxygen species (ROS) in zebrafish embryos were observed by DCFH-DA staining. Super oxide dimutese (SOD) and catalase (CAT) were determined with ELISA kits. Results: We found that DBP increased the oxidative stress level of zebrafish exposed to DBP, and the genes related to vascular development also increased. Meanwhile, the activities of SOD and CAT were greatly decreased after DBP exposure. In the rescue experiment, we found that the antioxidant astaxanthin and the small molecule VEGF inhibitor ZM-306,416 can reverse the vascular dysplasia caused by DBP. Conclusions: DBP induced vascular developmental toxicity by enhancing oxidative stress levels, activating HIF pathway, and interfering with the expression of vascular development-related pathways in zebrafish, results in the abnormal development of the subintestinal vessels in zebrafish.

As the key interface, the nitrate removal capacity of riparian zones is receiving close attention. Although naturally occurring organic compounds in this environment play a pivotal role in shaping microbial communities and influencing the nitrate removal capacity, the relevant research is inadequate. Given the complexity of riparian environments, in this study, we added representative natural organic matter (fulvic acid, butyric acid, naphthalene, starch, and sodium bicarbonate) as carbon conditions and incorporated magnetite to simulate riparian zone components. The study investigated the nitrate degradation efficiency and microbial responses under different natural carbon conditions in real iron-containing environments. Butyric acid exhibited the most efficient nitrate reduction, followed in descending order by naphthalene, starch, sodium bicarbonate, and humic acid. However, this did not imply that butyric acid efficiently removed nitrogen; instead, the nitrogen would circulate in the environment in the form of ammonium. Denitrification and DNRA were the primary drivers of nitrate reduction in each system, while naphthalene and humic acid systems also exhibited nitrification and mineralization. Nitrogen-fixing bacteria represent a unique microbial community in the butyrate system. Further, the synergistic degradation of naphthalene and nitrate demonstrated significant potential applications. High-throughput sequencing revealed that carbon conditions exerted selective pressure on microorganisms, driving Fe (Ⅱ)/Fe (Ⅲ) transformation by shaping the microbial community structure and influencing the nitrogen cycling process.