The spring snow cover(SC)over the western Tibetan Plateau(TP)(TPSC)(W_TPSC)and eastern TPSC(E_TPSC)have displayed remarkable decreasing and increasing trends,respectively,during 1985–2020.The current work investigate...The spring snow cover(SC)over the western Tibetan Plateau(TP)(TPSC)(W_TPSC)and eastern TPSC(E_TPSC)have displayed remarkable decreasing and increasing trends,respectively,during 1985–2020.The current work investigates the possible mechanisms accounting for these distinct TPSC changes.Our results indicate that the decrease in W_TPSC is primarily attributed to rising temperatures,while the increase in E_TPSC is closely linked to enhanced precipitation.Local circulation analysis shows that the essential system responsible for the TPSC changes is a significant anticyclonic system centered over the northwestern TP.The anomalous descending motion and adiabatic heating linked to this anticyclone leads to warmer temperatures and consequent snowmelt over the western TP.Conversely,anomalous easterly winds along the southern flank of this anticyclone serve to transport additional moisture from the North Pacific,leading to an increase in snowfall over the eastern TP.Further analysis reveals that the anomalous anticyclone is associated with an atmospheric wave pattern that originates from upstream regions.Springtime warming of the subtropical North Atlantic(NA)sea surface temperature(SST)induces an atmospheric pattern resembling a wave train that travels eastward across the Eurasian continent before reaching the TP.Furthermore,the decline in winter sea ice(SIC)over the Barents Sea exerts a persistent warming influence on the atmosphere,inducing an anomalous atmospheric circulation that propagates southeastward and strengthens the northwest TP anticyclone in spring.Additionally,an enhancement of subtropical stationary waves has resulted in significant increases in easterly moisture fluxes over the coastal areas of East Asia,which further promotes more snowfall over eastern TP.展开更多
Inflammatory bowel disease(IBD)is a serious disorder,and exploration of active compounds to treat it is necessary.An acidic polysaccharide named SUSP-4 was purified from Selaginella uncinata(Desv.)Spring,which contain...Inflammatory bowel disease(IBD)is a serious disorder,and exploration of active compounds to treat it is necessary.An acidic polysaccharide named SUSP-4 was purified from Selaginella uncinata(Desv.)Spring,which contained galacturonic acid,galactose,xylose,arabinose,and rhamnose with the main chain structure of→4)-α-d-GalAp-(1→and→6)-β-d-Galp-(1→and the branched structure of→5)-α-l-Araf-(1→.Animal experiments showed that compared with Model group,SUSP-4 significantly improved body weight status,disease activity index(DAI),colonic shortening,and histopathological damage,and elevated occludin and zonula occludens protein 1(ZO-1)expression in mice induced by dextran sulfate sodium salt(DSS).16S ribosomal RNA(rRNA)sequencing indicated that SUSP-4 markedly downregulated the level of Akkermansia and Alistipes.Metabolomics results confirmed that SUSP-4 obviously elevated thiamine levels compared with Model mice by adjusting thiamine metabolism,which was further confirmed by a targeted metabolism study.Fecal transplantation experiments showed that SUSP-4 exerted an anti-IBD effect by altering the intestinal flora in mice.A mechanistic study showed that SUSP-4 markedly inhibited macrophage activation by decreasing the levels of phospho-nuclear factor kappa-B(p-NF-κB)and cyclooxygenase-2(COX-2)and elevating NF-E2-related factor 2(Nrf2)levels compared with Model group.In conclusion,SUSP-4 affected thiamine metabolism by regulating Akkermania and inhibited macrophage activation to adjust NF-κB/Nrf2/COX-2-mediated inflammation and oxidative stress against IBD.This is the first time that plant polysaccharides have been shown to affect thiamine metabolism against IBD,showing great potential for in-depth research and development applications.展开更多
基金This research is funded by the National Natural Science Foundation of China(Grant No.42075050)Fundamental Research Funds for the Central Universities(Grant No.K20220232).
文摘The spring snow cover(SC)over the western Tibetan Plateau(TP)(TPSC)(W_TPSC)and eastern TPSC(E_TPSC)have displayed remarkable decreasing and increasing trends,respectively,during 1985–2020.The current work investigates the possible mechanisms accounting for these distinct TPSC changes.Our results indicate that the decrease in W_TPSC is primarily attributed to rising temperatures,while the increase in E_TPSC is closely linked to enhanced precipitation.Local circulation analysis shows that the essential system responsible for the TPSC changes is a significant anticyclonic system centered over the northwestern TP.The anomalous descending motion and adiabatic heating linked to this anticyclone leads to warmer temperatures and consequent snowmelt over the western TP.Conversely,anomalous easterly winds along the southern flank of this anticyclone serve to transport additional moisture from the North Pacific,leading to an increase in snowfall over the eastern TP.Further analysis reveals that the anomalous anticyclone is associated with an atmospheric wave pattern that originates from upstream regions.Springtime warming of the subtropical North Atlantic(NA)sea surface temperature(SST)induces an atmospheric pattern resembling a wave train that travels eastward across the Eurasian continent before reaching the TP.Furthermore,the decline in winter sea ice(SIC)over the Barents Sea exerts a persistent warming influence on the atmosphere,inducing an anomalous atmospheric circulation that propagates southeastward and strengthens the northwest TP anticyclone in spring.Additionally,an enhancement of subtropical stationary waves has resulted in significant increases in easterly moisture fluxes over the coastal areas of East Asia,which further promotes more snowfall over eastern TP.
基金the funding from the Spring City Plan of the High-Level Talent Promotion and Training Project of Kunming,China(Grant No.:2022SCP008)the Independent Research Fund of Yunnan Characteristic Plant Extraction Laboratory,China(Grant No.:2022YKZY001).
文摘Inflammatory bowel disease(IBD)is a serious disorder,and exploration of active compounds to treat it is necessary.An acidic polysaccharide named SUSP-4 was purified from Selaginella uncinata(Desv.)Spring,which contained galacturonic acid,galactose,xylose,arabinose,and rhamnose with the main chain structure of→4)-α-d-GalAp-(1→and→6)-β-d-Galp-(1→and the branched structure of→5)-α-l-Araf-(1→.Animal experiments showed that compared with Model group,SUSP-4 significantly improved body weight status,disease activity index(DAI),colonic shortening,and histopathological damage,and elevated occludin and zonula occludens protein 1(ZO-1)expression in mice induced by dextran sulfate sodium salt(DSS).16S ribosomal RNA(rRNA)sequencing indicated that SUSP-4 markedly downregulated the level of Akkermansia and Alistipes.Metabolomics results confirmed that SUSP-4 obviously elevated thiamine levels compared with Model mice by adjusting thiamine metabolism,which was further confirmed by a targeted metabolism study.Fecal transplantation experiments showed that SUSP-4 exerted an anti-IBD effect by altering the intestinal flora in mice.A mechanistic study showed that SUSP-4 markedly inhibited macrophage activation by decreasing the levels of phospho-nuclear factor kappa-B(p-NF-κB)and cyclooxygenase-2(COX-2)and elevating NF-E2-related factor 2(Nrf2)levels compared with Model group.In conclusion,SUSP-4 affected thiamine metabolism by regulating Akkermania and inhibited macrophage activation to adjust NF-κB/Nrf2/COX-2-mediated inflammation and oxidative stress against IBD.This is the first time that plant polysaccharides have been shown to affect thiamine metabolism against IBD,showing great potential for in-depth research and development applications.
