Anti-fatigue Effect of Water Extract from Centella asiatica(L.)Urban on Mice

[Objectives]To study the anti-fatigue effect of water extract from Centella asiatica(L.)Urban on mice.[Methods]After intragastric administration of low,medium and high concentration of water extract from Centella asiatica(L.)Urban for 14 d,the rotarod time and the content of serum lactic acid in mice were determined,respectively.[Results]Compared with the control group,the rotarod time of mice in the low and medium concentration groups was significantly prolonged(P<0.05),but there was no significant difference between the control group and the high concentration group;the content of serum lactic acid in the medium concentration group was significantly lower than that in the control group(P<0.01),but there was no significant difference between low concentration group and high concentration group and the control group.[Conclusions]A certain concentration of water extract from Centella asiatica(L.)Urban had a good anti-fatigue effect.

Enhancing nitrogen removal in constructed wetlands: The role of influent substrate concentrations in integrated vertical-flow systems

Recent advancements in constructed wetlands(CWs)have highlighted the imperative of enhancing nitrogen(N)removal efficiency.However,the variability in influent substrate concentrations presents a challenge in optimizing N removal strategies due to its impact on removal efficiency and mechanisms.Here we show the interplay between influent substrate concentration and N removal processes within integrated vertical-flow constructed wetlands(IVFCWs),using wastewaters enriched with NO_(3)^(-)-N and NH4þ-N at varying carbon to nitrogen(C/N)ratios(1,3,and 6).In the NO_(3)^(-)-N enriched systems,a positive correlation was observed between the C/N ratio and total nitrogen(TN)removal efficiency,which markedly increased from 13.46±2.23%to 87.00±2.37%as the C/N ratio escalated from 1 to 6.Conversely,in NH4þ-N enriched systems,TN removal efficiencies in the A-6 setup(33.69±4.83%)were marginally 1.25 to 1.29 times higher than those in A-3 and A-1 systems,attributed to constraints in dissolved oxygen(DO)levels and alkalinity.Microbial community analysis and metabolic pathway assessment revealed that anaerobic denitrification,microbial N assimilation,and dissimilatory nitrate reduction to ammonium(DNRA)predominated in NO_(3)^(-)-N systems with higher C/N ratios(C/N 3).In contrast,aerobic denitrification and microbial N assimilation were the primary pathways in NH4þ-N systems and low C/N NO_(3)^(-)-N systems.A mass balance approach indicated denitrification and microbial N assimilation contributed 4.12-47.12%and 8.51e38.96%in NO_(3)^(-)-N systems,respectively,and 0.55e17.35%and 7.83e33.55%in NH4þ-N systems to TN removal.To enhance N removal,strategies for NO_(3)-N dominated systems should address carbon source limitations and electron competition between denitrification and DNRA processes,while NH4þ-N dominated systems require optimization of carbon utilization pathways,and ensuring adequate DO and alkalinity supply.