Dietary supplementation of benzoic acid and essential oils combination enhances intestinal resilience against LPS stimulation in weaned piglets

Background The benefits of combining benzoic acid and essential oils(BAO)to mitigate intestinal impairment during the weaning process have been well established,while the detailed underlying mechanism has not been fully elucidated.Previous research has primarily focused on the reparative effects of BAO on intestinal injury,while neglecting its potential in enhancing intestinal stress resistance.Methods In this study,we investigated the pre-protective effect of BAO against LPS-induced stress using a modified experimental procedure.Piglets were pre-supplemented with BAO for 14 d,followed by a challenge with LPS or saline to collect blood and intestinal samples.Results Our findings demonstrated that BAO supplementation led to significant improvements in piglets’final weight,average daily gain,and feed intake/body gain ratio.Additionally,BAO supplementation positively influenced the composition of intestinal microbiota,increasing beneficial Actinobacteriota and Alloprevotella while reducing harmful Desulfobacterota,Prevotella and Oscillospira.Furthermore,BAO supplementation effectively mitigated oxidative disturbances and inflammatory responses induced by acute LPS challenge.This was evidenced by elevated levels of T-AOC,SOD,and GSH,as well as decreased levels of MDA,TNF-α,and IL-6 in the plasma.Moreover,piglets subjected to LPS challenge and pre-supplemented with BAO exhibited significant improvements in intestinal morphological structure and enhanced integrity,as indicated by restored expression levels of Occludin and Claudin-1 compared to the non-supplemented counterparts.Further analysis revealed that BAO supplementation enhanced the jejunal antioxidative capacity by increasing GSH-Px levels and decreasing MDA levels under the LPS challenge and stimulated the activation of the Nrf2 signaling pathway.Additionally,the reduction of TLR4/NF-κB/MAPK signaling pathways activation and proinflammatory factor were also observed in the jejunal of those piglets fed with BAO.Conclusions In summary,our study demonstrates that pre-supplementation of BAO enhances the anti-stress capacity of weaned piglets by improving intestinal microbiota composition,reinforcing the intestinal barrier,and enhancing antioxidative and anti-inflammatory capabilities.These effects are closely associated with the activation of Nrf2 and TLR4/NF-κB/MAPK signaling pathways.

Restored intestinal integrity,nutrients transporters,energy metabolism,antioxidative capacity and decreased harmful microbiota were associated with IUGR piglet's catch-up growth before weanling

Background:Intrauterine growth restriction(IUGR)is a major inducer of higher morbidity and mortality in the pig industry and catch-up growth(CUG)before weanling could significantly restore this negative influence.But there was limited knowledge about the underlying mechanism of CUG occurrence.Methods:Eighty litters of newborn piglets were divided into normal birth weight(NBW)and IUGR groups according to birth weight.At 26 d,those piglets with IUGR but over average body weight of eighty litters of weaned piglets were considered as CUG,and the piglets with IUGR still below average body weight were considered as NCUG.This study was conducted to systemically compare the intestinal difference among NBW,CUG and NCUG weaned piglets considering the crucial role of the intestine for piglet growth.Results:The results indicated that the m RNA expression of nutrients(amino acids,glucose,and fatty acids)transporters,and mitochondrial electron transport chain(ETC)I were upregulated in CUG piglets'gut with improved morphology compared with those NCUG,as well as the ratio of P-AMPK/AMPK protein expression which is the indicator of energy metabolism.Meanwhile,CUG piglet's gut showed higher antioxidative capacity with increased SOD and GSHPx activity,decreased MDA levels,as well as higher m RNA expressions of Nrf2,Keap1,SOD,and GSH-Px.Furthermore,inflammatory parameters including TNF-α,IL-1β,IL-6,and IL-12 factors,and the activation of MAPK and NF-κB signaling pathways were significantly elevated in the NCUG intestine,while the protein expression of ZO-1,Occludin and Claudin-1 was reduced.The alpha diversity of fecal microbiota was higher in CUG piglets in contrast with NCUG piglets,and the increased beneficial bacteria and decreased pathogenic bacteria was also observed in CUG piglets.Conclusions:CUG piglet's intestine showed comprehensive restoration including higher nutrients transport,energy metabolism,antioxidant capacity,and intestinal physical barrier,while lower oxidative stress,inflammatory response,and pathogenic microbiota.

Cation-πinteractions regulate electrocatalytic water oxidation over iridium single atoms supported on conjugated polymers

Designing cost-effective and high-performing metal catalysts is significant for many renewable energy conversion technologies.Lowering metal loading without sacrificing activity and durability is highly desired for the catalyst design,especially for those reactions where the noble metals deliver the best catalyzing performance.Single-atom catalysts(SACs)with maximal metalatom utilization,homogeneous and tailorable active sites have emerged as promising catalyst candidates,where the local coordination structures of the metal atoms in SACs largely determine the reaction kinetics.Previous design strategies of constructing strong metal-support interactions can stabilize the individual metal atoms in SACs,but present obstacles to provide a flexible manipulation platform for elaborately tailoring the coordination structures to achieve performance optimization towards a specifically targeted reaction.Here,for the proof-of-concept study,we report a novel design of SAC with iridium(Ir)single atoms supported on conjugated polymer,in which the adsorption energies of reaction intermediates on Ir atoms and the reaction kinetics towards acidic water oxidation can be readily optimized through modulating the formed cation-πinteractions that can be tailored by adjusting the molecular structures of conjugated polymers.This strategy establishes a general route to develop targeted SACs for various catalytic reactions.

海南岛主要河流物理生境健康评价方法及应用

热带海岛是地球上生物多样性最丰富的地区之一,热带海岛河流相比大陆河流具有短小而多样的特点。开展热带海岛河流物理生境健康评价对于生物多样性保护、水资源管理和经济发展都具有重要意义。现阶段河流物理生境健康评价多基于监测点位、样方地面监测,无法兼顾代表性、便利性和安全性,并且费时费力,很难全面准确地反映河流物理生境状况。以海南岛南渡江流域、昌化江流域和万泉河流域三大流域主要河流为研究对象,基于遥感监测构建了海南岛河流物理生境健康评价指标体系,采用层次分析法和专家打分法确定指标权重和评价模型,开展了三大流域27条河流物理生境健康评价。结果显示:(1)南渡江流域、昌化江流域、万泉河流域均以森林和农田两类生态系统类型为主,三大流域以农田生态系统占比最大。(2)三大流域河流河岸带植被覆盖度整体上较高,达70%以上,以人工经济林为主;自然岸线率整体不高,均值为41.93%,河岸带范围受人类活动影响较大。(3)三大流域河流物理生境评价等级以亚健康状态为主,其次为不健康状态。本研究基于现阶段海南自由贸易港建设生态环境保护工作的重大需求,可为精准实施流域生态环境保护、治理工作提供数据支撑,为海南岛水生态考核等相关评价标准的阈值设定提供参考。