Ny-Ålesund,located in Arctic Svalbard,is one of the most sensitive areas on Earth to global warming.In recent years,accelerated glacier ablation has become remarkable in Ny-Ålesund.Glacial meltwaters dischar...Ny-Ålesund,located in Arctic Svalbard,is one of the most sensitive areas on Earth to global warming.In recent years,accelerated glacier ablation has become remarkable in Ny-Ålesund.Glacial meltwaters discharge a substantial quantity of materials to the ocean,affecting downstream ecosystems and adjacent oceans.In August 2015,various water samples were taken near Ny-Ålesund,including ice marginal meltwater,proglacial meltwater,supraglacial meltwater,englacial meltwater,and groundwater.Trace metals(Al,Cr,Mn,Fe,Co,Cu,Zn,Cd,and Pb),major ions,alkalinity,pH,dissolved oxygen,water temperature and electric conductivity were also measured.Major ions were mainly controlled by chemical weathering intensity and reaction types,while trace metals were influenced by both chemical weathering and physicochemical control upon their mobility.Indeed,we found that Brøggerbreen was dominated by carbonate weathering via carbonation of carbonate,while Austre Lovénbreen and Pedersenbreen were dominated by sulfide oxidation coupled with carbonate dissolution with a doubled silicate weathering.The higher enrichment of trace metals in supraglacial meltwater compared to ice marginal and proglacial meltwater suggested anthropogenic pollution from atmospheric deposition.In ice marginal and proglacial meltwater,principal component analysis indicated that trace metals like Cr,Al,Co,Mn and Cd were correlated to chemical weathering.This implies that under accelerated glacier retreat,glacier-derived chemical components are subjected to future changes in weathering types and intensity.展开更多
Helicobacter pylori is a risk factor for the development of peptic ulcers with autophagy dysfunction.Omeprazole was widely known as the first-line regimen for H.pylori-associated gastritis.Objectives:The objective of ...Helicobacter pylori is a risk factor for the development of peptic ulcers with autophagy dysfunction.Omeprazole was widely known as the first-line regimen for H.pylori-associated gastritis.Objectives:The objective of this work was to assess the role of omeprazole on cell pyroptosis and autophagy.Methods:The clinical samples were collected.Quantitative polymerase chain reaction,western blotting,enzyme linked immunosorbent assay,and immunofluorescence(IF)analysis were conducted to reveal the mechanism of omeprazole on cell pyroptosis and autophagy.Results:The results revealed that omeprazole could decrease cell pyroptosis,which was attributed to the downregulation of cleaved caspase-1 expression,resulting in the inhibition of gasdermin E and interleukin-18/1βmaturation and secretion as well as the resolution of inflammation.Mechanistically,omeprazole treatment led to drastic downregulation of mammalian target of rapamycin(mTOR)activity was observed in BGC823 cells,leading to enhanced autophagy characterized by increased LC3II expression,which further reduced cell pyroptosis.This omeprazole-mediated phenomenon was enhanced after phosphodiesterase-4(PDE4)inhibitor dipyridamole(DIP)treatment.In addition,activation of mTOR by MHY1485 could rescue the suppression of cell pyroptosis induced by omeprazole.Most importantly,IF analysis suggested that phosphorylation of mTOR and PDE4 activity and caspase-1 were enhanced in H.pylori-infected gastric mucosa.Conclusion:These findings indicate that omeprazole suppresses cell pyroptosis through PDE4-mediated autophagy in gastric epithelial cells,and DIP enhanced the omeprazole-mediated inhibition of cell pyroptosis,implying that DIP is an alternative combined therapy strategy in improving the treatment of patients with H.pylori infection.展开更多
Bound states in the continuum(BICs) are spatially localized states with energy embedded in the continuum spectrum of extended states. The combination of BICs physics and nontrivial band topology theory givs rise to to...Bound states in the continuum(BICs) are spatially localized states with energy embedded in the continuum spectrum of extended states. The combination of BICs physics and nontrivial band topology theory givs rise to topological BICs, which are robust against disorders and meanwhile, the merit of conventional BICs is attracting wide attention recently. Here, we report valley edge states as topological BICs, which appear at the domain wall between two distinct valley topological phases. The robustness of such BICs is demonstrated. The simulations and experiments show great agreement. Our findings of valley related topological BICs shed light on both BICs and valley physics, and may foster innovative applications of topological acoustic devices.展开更多
Dirac semimetals,the materials featuring fourfold degenerate Dirac points,are critical states of topologically distinct phases.Such gapless topological states have been accomplished by a band-inversion mechanism,in wh...Dirac semimetals,the materials featuring fourfold degenerate Dirac points,are critical states of topologically distinct phases.Such gapless topological states have been accomplished by a band-inversion mechanism,in which the Dirac points can be annihilated pairwise by perturbations without changing the symmetry of the system.Here,we report an experimental observation of Dirac points that are enforced completely by the crystal symmetry using a nonsymmorphic three-dimensional phononic crystal.Intriguingly,our Dirac phononic crystal hosts four spiral topological surface states,in which the surface states of opposite helicities intersect gaplessly along certain momentum lines,as confirmed by additional surface measurements.The novel Dirac system may release new opportunities for studying elusive(pseudo)and offer a unique prototype platform for acoustic applications.展开更多
基金The National Natural Science Foundation of China under contract Nos 42076227,41676175 and 41276202the Chinese Arctic and Antarctic Administration under contract No.CHINARE-YRS2015-21+1 种基金the Shanghai Pilot Program for Basic Re-search-Shanghai Jiao Tong University under contract No.21TQ1400201the Shanghai Frontiers Science Center of Polar Science(SCOPS).
文摘Ny-Ålesund,located in Arctic Svalbard,is one of the most sensitive areas on Earth to global warming.In recent years,accelerated glacier ablation has become remarkable in Ny-Ålesund.Glacial meltwaters discharge a substantial quantity of materials to the ocean,affecting downstream ecosystems and adjacent oceans.In August 2015,various water samples were taken near Ny-Ålesund,including ice marginal meltwater,proglacial meltwater,supraglacial meltwater,englacial meltwater,and groundwater.Trace metals(Al,Cr,Mn,Fe,Co,Cu,Zn,Cd,and Pb),major ions,alkalinity,pH,dissolved oxygen,water temperature and electric conductivity were also measured.Major ions were mainly controlled by chemical weathering intensity and reaction types,while trace metals were influenced by both chemical weathering and physicochemical control upon their mobility.Indeed,we found that Brøggerbreen was dominated by carbonate weathering via carbonation of carbonate,while Austre Lovénbreen and Pedersenbreen were dominated by sulfide oxidation coupled with carbonate dissolution with a doubled silicate weathering.The higher enrichment of trace metals in supraglacial meltwater compared to ice marginal and proglacial meltwater suggested anthropogenic pollution from atmospheric deposition.In ice marginal and proglacial meltwater,principal component analysis indicated that trace metals like Cr,Al,Co,Mn and Cd were correlated to chemical weathering.This implies that under accelerated glacier retreat,glacier-derived chemical components are subjected to future changes in weathering types and intensity.
基金supported by National Natural Science Foundation of China(No.82200607)Guangdong Basic and Applied Basic Research Foundation(Nos.2020A1515110109,2021A1515012194,2023A1515030064)+3 种基金Basic and Applied Research Project of Guangzhou Municipal Science and Technology Project(No.202201020631)Guangzhou Medical Key Disciplines and Specialties(No.011006003)Guangzhou Key Laboratory of Pediatric Inflammatory Bowel Disease(No.2023A03J0866)National Health Commission Key Laboratory of Tropical Disease Prevention and Control(2022NHCTDCKFKT21001).
文摘Helicobacter pylori is a risk factor for the development of peptic ulcers with autophagy dysfunction.Omeprazole was widely known as the first-line regimen for H.pylori-associated gastritis.Objectives:The objective of this work was to assess the role of omeprazole on cell pyroptosis and autophagy.Methods:The clinical samples were collected.Quantitative polymerase chain reaction,western blotting,enzyme linked immunosorbent assay,and immunofluorescence(IF)analysis were conducted to reveal the mechanism of omeprazole on cell pyroptosis and autophagy.Results:The results revealed that omeprazole could decrease cell pyroptosis,which was attributed to the downregulation of cleaved caspase-1 expression,resulting in the inhibition of gasdermin E and interleukin-18/1βmaturation and secretion as well as the resolution of inflammation.Mechanistically,omeprazole treatment led to drastic downregulation of mammalian target of rapamycin(mTOR)activity was observed in BGC823 cells,leading to enhanced autophagy characterized by increased LC3II expression,which further reduced cell pyroptosis.This omeprazole-mediated phenomenon was enhanced after phosphodiesterase-4(PDE4)inhibitor dipyridamole(DIP)treatment.In addition,activation of mTOR by MHY1485 could rescue the suppression of cell pyroptosis induced by omeprazole.Most importantly,IF analysis suggested that phosphorylation of mTOR and PDE4 activity and caspase-1 were enhanced in H.pylori-infected gastric mucosa.Conclusion:These findings indicate that omeprazole suppresses cell pyroptosis through PDE4-mediated autophagy in gastric epithelial cells,and DIP enhanced the omeprazole-mediated inhibition of cell pyroptosis,implying that DIP is an alternative combined therapy strategy in improving the treatment of patients with H.pylori infection.
基金supported by the National Key R&D Program of China (2022YFA1404500,and 2022YFA1404900)National Natural Science Foundation of China (12074128,12004286,12104347,12222405,12374419,and 12374409)Guangdong Basic and Applied Basic Research Foundation (2021B1515020086,and 2022B1515020102)。
文摘Bound states in the continuum(BICs) are spatially localized states with energy embedded in the continuum spectrum of extended states. The combination of BICs physics and nontrivial band topology theory givs rise to topological BICs, which are robust against disorders and meanwhile, the merit of conventional BICs is attracting wide attention recently. Here, we report valley edge states as topological BICs, which appear at the domain wall between two distinct valley topological phases. The robustness of such BICs is demonstrated. The simulations and experiments show great agreement. Our findings of valley related topological BICs shed light on both BICs and valley physics, and may foster innovative applications of topological acoustic devices.
基金supported by the National Key R&D Program of China(Grant 2018YFA0305800)the National Natural Science Foundation of China(Grant Nos.,11774275,11890701,11674250,and 11534013)+1 种基金the Natural Science Foundation of Hubei Province(Grant No.2017CFA042)the Young Top-notch Talent for Ten Thousand Talent Program(2019-2022).
文摘Dirac semimetals,the materials featuring fourfold degenerate Dirac points,are critical states of topologically distinct phases.Such gapless topological states have been accomplished by a band-inversion mechanism,in which the Dirac points can be annihilated pairwise by perturbations without changing the symmetry of the system.Here,we report an experimental observation of Dirac points that are enforced completely by the crystal symmetry using a nonsymmorphic three-dimensional phononic crystal.Intriguingly,our Dirac phononic crystal hosts four spiral topological surface states,in which the surface states of opposite helicities intersect gaplessly along certain momentum lines,as confirmed by additional surface measurements.The novel Dirac system may release new opportunities for studying elusive(pseudo)and offer a unique prototype platform for acoustic applications.
