ABSTRACT
Pyran- and furanocoumarins are key representatives of tetrahydropyrans and tetrahydrofurans, respectively, exhibiting diverse physiological and medical bioactivities. However, the biosynthetic mechanisms for their core structures remain poorly understood. Here we combined multiomics analyses of biosynthetic enzymes in Peucedanum praeruptorum and in vitro functional verification and identified two types of key enzymes critical for pyran and furan ring biosynthesis in plants. These included three distinct P. praeruptorum prenyltransferases (PpPT1-3) responsible for the prenylation of the simple coumarin skeleton 7 into linear or angular precursors, and two novel CYP450 cyclases (PpDC and PpOC) crucial for the cyclization of the linear/angular precursors into either tetrahydropyran or tetrahydrofuran scaffolds. Biochemical analyses of cyclases indicated that acid/base-assisted epoxide ring opening contributed to the enzyme-catalyzed tetrahydropyran and tetrahydrofuran ring refactoring. The possible acid/base-assisted catalytic mechanisms of the identified cyclases were theoretically investigated and assessed using site-specific mutagenesis. We identified two possible acidic amino acids Glu303 in PpDC and Asp301 in PpOC as vital in the catalytic process. This study provides new enzymatic tools in the epoxide formation/epoxide-opening mediated cascade reaction and exemplifies how plants become chemically diverse in terms of enzyme function and catalytic process.
ABSTRACT
Objective@#To explore the relationship between adolescent sports participation and aggression, so as to provide a reference basis for sports interventions aimed at reducing adolescent aggression.@*Methods@#The search databases used in the study included China National Knowledge Infrastructure, Vipo, Wanfang, Web of Science, Ebsco, Pro Quest, and PubMed, and the search period was from the construction of the database to October 22, 2023. The search terms for sports participation were "sport" "exercise" "exercise" "physical activity" "physical activity"; the search terms for aggressive behavior were "assault" "aggressive behavior" "aggression"; the search terms for aggressive behavior were "assault" "aggressive behavior" "aggression" "bullying", and "violence", and the above keywords were jointly searched. Foreign language data were searched using Web of Science, Ebsco, Pro Quest, PubMed and supplemented by Google Scholar. The search terms for sports participation were sport, athletics, exercise, train, fitness, physical exercise, physical activity, physical education; and the search terms for aggressive behavior were aggression, bullying, violence, atrocity, fighting, aggressive behavior, physical assault; the above keywords were jointly searched. Statistical analysis was performed using CMA 3.0 software.@*Results@#A total of 20 studies with 80 effect sizes and 9 308 subjects were included. The Metaanalysis showed that adolescent sports participation was moderately negatively correlated with indicators of aggression (r=-0.11), physical aggression (r=-0.14), verbal aggression (r=-0.14), and hostility (r=-0.16), and weakly negatively correlated with indicators of anger (r=-0.08) (P<0.05). Aggressive behavior was influenced by gender, school stage, mode of exercise, and the sports participants region (P<0.05).@*Conclusions@#Exercise participation has a positive impact on reducing aggressive behavior in adolescents, and mode of exercise, age, gender, and region are moderating variables in the relationship. Schools can reduce adolescent aggression by developing exercise and physical education interventions.
ABSTRACT
Objective To study the effective hemostatic method for treating multiple trauma accompanied with hemorrhagic shock to increase the existence rate. Methods In treating 5 patients of multiple tauma accompanied with hemorrhagic shock, We used radiological embolism to injuried parenchymatous organs and injuried vessels to arrest the bleeding at first. After shock recovered, prompt exploration was made to repair injuried hollow viscus. Results After embolism and bleeding arrested, shocks in all 5 patients were corrected in short time; and no serious active hemorrhage was found after abdominal operation to repair the hollow viscus. All 5 patients survived after the operation. Conclusions The radiological embolism is simple,and has the little trauma and a good hemostatic effect,and needs short time. The method for treating multiple trauma can improve the salvage rate of multiple trauma accompanied with hemorrhagic shock and fit the treatment principle of multiple trauma.