The Niangzhong diabase dikes,dated at 138.1±0.4 Ma,are located within the outcrop area of the Comei large igneous province(LIP).These diabase samples can be divided into two groups:samples in Group 1 show varying...The Niangzhong diabase dikes,dated at 138.1±0.4 Ma,are located within the outcrop area of the Comei large igneous province(LIP).These diabase samples can be divided into two groups:samples in Group 1 show varying MgO(1.50 wt.%-10.25 wt.%)and TiO_(2)(0.85 wt.%-4.63 wt.%)contents,and enriched initial isotope compositions(^(87)Sr/^(86)Sr(t)=0.7056-0.7112,ε_(Nd)(t)=-0.3-+3.8),with OIB-like REEs and trace elements patterns,resulting from low degree melting of garnet-bearing lherzolite mantle sources;in contrast,samples in Group 2 show limited MgO(4.14 wt.%-7.75 wt.%)and TiO_(2)(0.98 wt.%-1.69 wt.%)contents,and depleted initial isotope compositions(^(87)Sr/^(86)Sr(t)=0.7075-0.7112,ε_(Nd)(t)=+5.5-+6.2),with N-MORB-like REEs and trace elements patterns,resulting from relatively high degree melting of spinel-bearing lherzolite mantle source.Combined with the published representative data about Comei LIP,we summarize that the source components for Comei LIP products include OIB end-member,enriched OIB end-member,and N-MORB end-member,respectively.Melts modeling suggests that magmas in the Comei LIP evolve in a relatively high oxygen fugacity condition,which influenced their fractionation sequences and led to systematic changes of TiO_(2)contents,Ti/Y and Ti/Ti*ratios.From the spatial and temporal distribution of above three end-member samples,deep process of Kerguelen plume during the Comei LIP formation can be interpreted as the interaction among the Kerguelen plume,the overlying lithospheric mantle,and the upwelling asthenosphere.The magmatism of Comei LIP began at~140 Ma and then lasted and peaked at~132 Ma with the progressively lithospheric thinning of eastern Gondwana upon the impact of Kerguelen plume.展开更多
Two amphiboles and a syn-metamorphic quartz vein from the Yuka terrane,North Qaidam,western China,have been analyzed by joint40Ar/39Ar crushing in vacuo and stepwise heating techniques.The crushing in vacuo results pr...Two amphiboles and a syn-metamorphic quartz vein from the Yuka terrane,North Qaidam,western China,have been analyzed by joint40Ar/39Ar crushing in vacuo and stepwise heating techniques.The crushing in vacuo results provide information to directly constrain the timing of fluid activity and the age of amphibolite-facies retrogression.The stepwise heating results could further be used to decipher the thermal history of the UHP rocks.Amphiboles from amphibolites and quartz vein within garnetamphibolite lens analyzed by in vacuo crushing yield similarly shaped age spectra and exhibit relatively flat age plateaus for the last several steps.The characteristics of gas release patterns and geochronological data testify to the presence of significant excess40Ar within the fluid inclusions.The age plateaux with weighted mean ages（WMA） ranges from 488 to 476 Ma for amphiboles and 403 Ma for quartz（2σ）.These data points constitute amphibole WMA yielding excellent isochrons with isochron ages of 469 and 463 Ma with initial40Ar/36Ar ratios of 520 and 334,respectively.The isochron ages are interpreted to represent initial amphibolite-facies retrogression.The data points constituting the quartz age plateaux give an isochron age of 405 Ma with initial40Ar/36Ar ratio of 295,recording a significant aqueous fluid flow episode during the early Devonian.Age spectra obtained by stepwise heating of amphibole residues remaining after crushing experiments are characterized by younger and relatively complex age spectra,which are probably influenced by the combined effects of resetting argon and/or mineral inclusions.Nevertheless,we note that the spectra shapes have features in common:excluding the last two steps,minimum apparent ages are found at temperatures of around 500 ℃,corresponding to319 and 249 Ma,perhaps representing the time of isotopic resetting or resulting from release gas from mineral inclusions of,e.g.,biotite or feldspar.Maximum apparent ages are obtained at temperatures of around 800℃,corresponding to 418 and 413 Ma,which probably reflect mixed ages of radiogenic resetting and original amphibole.These results indicate that the Yuka eclogites and their retrogressed equivalents were overprinted by multiple thermal events in the Silurian and possibly as young as the Triassic.展开更多
Berberine has been shown to reduce acute liver injury although the underlying mechanism is not fully understood. Because of the anatomic connection, the liver is constantly exposed to gut-derived bacterial products an...Berberine has been shown to reduce acute liver injury although the underlying mechanism is not fully understood. Because of the anatomic connection, the liver is constantly exposed to gut-derived bacterial products and metabolites. In this study, we showed that berberine has beneficial effects on both hepatotoxicity and intestinal damage in a rat model of chronic or acute liver injury. Microbiota transplantation from the rats with chronic hepatotoxicity could aggravate acute hepatotoxicity in mice treated with diethylnitrosamine(DEN). In rat models with gut homeostasis disruption induced by penicillin or dextran sulfate sodium(DSS), their fecal microbiota could also cause an enhanced hepatotoxicity of recipient mice. When treated with berberine,the DSS-induced enteric dysbacteriosis could be mitigated and their fecal bacteria were able to reduce acute hepatotoxicity in recipient mice. This study indicates that berberine could improve intestinal dysbacteriosis, which reduces the hepatotoxicity caused by pathological or pharmacological intervention. Fecal microbiota transplantation might be a useful method to directly explore homeostatic alteration in gut microbiota.展开更多
基金supported by the Second Tibetan Plateau Scientific Expedition and Research(No.2019QZKK0702)the National Natural Science Foundation of China(Nos.92055202,41873023,42102059)+3 种基金the China Geological Survey(No.DD20190057)the National Key Research and Development Project of China(No.2016YFC0600304)the Basic Scientific Research Fund of Key Laboratory of Deep-Earth Dynamics of Ministry of Natural Resources(Nos.J1901-1,J190110)the National Foundation from China Scholarship Council。
文摘The Niangzhong diabase dikes,dated at 138.1±0.4 Ma,are located within the outcrop area of the Comei large igneous province(LIP).These diabase samples can be divided into two groups:samples in Group 1 show varying MgO(1.50 wt.%-10.25 wt.%)and TiO_(2)(0.85 wt.%-4.63 wt.%)contents,and enriched initial isotope compositions(^(87)Sr/^(86)Sr(t)=0.7056-0.7112,ε_(Nd)(t)=-0.3-+3.8),with OIB-like REEs and trace elements patterns,resulting from low degree melting of garnet-bearing lherzolite mantle sources;in contrast,samples in Group 2 show limited MgO(4.14 wt.%-7.75 wt.%)and TiO_(2)(0.98 wt.%-1.69 wt.%)contents,and depleted initial isotope compositions(^(87)Sr/^(86)Sr(t)=0.7075-0.7112,ε_(Nd)(t)=+5.5-+6.2),with N-MORB-like REEs and trace elements patterns,resulting from relatively high degree melting of spinel-bearing lherzolite mantle source.Combined with the published representative data about Comei LIP,we summarize that the source components for Comei LIP products include OIB end-member,enriched OIB end-member,and N-MORB end-member,respectively.Melts modeling suggests that magmas in the Comei LIP evolve in a relatively high oxygen fugacity condition,which influenced their fractionation sequences and led to systematic changes of TiO_(2)contents,Ti/Y and Ti/Ti*ratios.From the spatial and temporal distribution of above three end-member samples,deep process of Kerguelen plume during the Comei LIP formation can be interpreted as the interaction among the Kerguelen plume,the overlying lithospheric mantle,and the upwelling asthenosphere.The magmatism of Comei LIP began at~140 Ma and then lasted and peaked at~132 Ma with the progressively lithospheric thinning of eastern Gondwana upon the impact of Kerguelen plume.
基金funded by the Chinese Academy Sciences-Royal Netherlands Academy of Arts and Sciences(CAS-KNAW)Joint PhD Training Programme(ISK/3523/PhD)the joint research project between the CAS and the De Koninklijke Nederlandse Akademie van Wetenschappen(06CDP002)
文摘Two amphiboles and a syn-metamorphic quartz vein from the Yuka terrane,North Qaidam,western China,have been analyzed by joint40Ar/39Ar crushing in vacuo and stepwise heating techniques.The crushing in vacuo results provide information to directly constrain the timing of fluid activity and the age of amphibolite-facies retrogression.The stepwise heating results could further be used to decipher the thermal history of the UHP rocks.Amphiboles from amphibolites and quartz vein within garnetamphibolite lens analyzed by in vacuo crushing yield similarly shaped age spectra and exhibit relatively flat age plateaus for the last several steps.The characteristics of gas release patterns and geochronological data testify to the presence of significant excess40Ar within the fluid inclusions.The age plateaux with weighted mean ages（WMA） ranges from 488 to 476 Ma for amphiboles and 403 Ma for quartz（2σ）.These data points constitute amphibole WMA yielding excellent isochrons with isochron ages of 469 and 463 Ma with initial40Ar/36Ar ratios of 520 and 334,respectively.The isochron ages are interpreted to represent initial amphibolite-facies retrogression.The data points constituting the quartz age plateaux give an isochron age of 405 Ma with initial40Ar/36Ar ratio of 295,recording a significant aqueous fluid flow episode during the early Devonian.Age spectra obtained by stepwise heating of amphibole residues remaining after crushing experiments are characterized by younger and relatively complex age spectra,which are probably influenced by the combined effects of resetting argon and/or mineral inclusions.Nevertheless,we note that the spectra shapes have features in common:excluding the last two steps,minimum apparent ages are found at temperatures of around 500 ℃,corresponding to319 and 249 Ma,perhaps representing the time of isotopic resetting or resulting from release gas from mineral inclusions of,e.g.,biotite or feldspar.Maximum apparent ages are obtained at temperatures of around 800℃,corresponding to 418 and 413 Ma,which probably reflect mixed ages of radiogenic resetting and original amphibole.These results indicate that the Yuka eclogites and their retrogressed equivalents were overprinted by multiple thermal events in the Silurian and possibly as young as the Triassic.
基金supported by the projects of the National Key Research Program of China (2016YFC1101402)the National Natural Science Foundation of China (31371440, 31571477)Program of Shanghai Academic/Technology Research Leader (16XD1403300)
文摘Berberine has been shown to reduce acute liver injury although the underlying mechanism is not fully understood. Because of the anatomic connection, the liver is constantly exposed to gut-derived bacterial products and metabolites. In this study, we showed that berberine has beneficial effects on both hepatotoxicity and intestinal damage in a rat model of chronic or acute liver injury. Microbiota transplantation from the rats with chronic hepatotoxicity could aggravate acute hepatotoxicity in mice treated with diethylnitrosamine(DEN). In rat models with gut homeostasis disruption induced by penicillin or dextran sulfate sodium(DSS), their fecal microbiota could also cause an enhanced hepatotoxicity of recipient mice. When treated with berberine,the DSS-induced enteric dysbacteriosis could be mitigated and their fecal bacteria were able to reduce acute hepatotoxicity in recipient mice. This study indicates that berberine could improve intestinal dysbacteriosis, which reduces the hepatotoxicity caused by pathological or pharmacological intervention. Fecal microbiota transplantation might be a useful method to directly explore homeostatic alteration in gut microbiota.
