位于青藏高原与黄土高原过渡带的甘肃武都万象洞石笋WXSM51和WXSM52提供了M IS 5(118~79kaB.P.)高分辨率的1δ8O记录。研究表明,万象洞石笋1δ8O值与夏季风强度呈负相关关系,与我国西南部的贵州董歌洞石笋1δ8O记录有良好的对应关系,并...位于青藏高原与黄土高原过渡带的甘肃武都万象洞石笋WXSM51和WXSM52提供了M IS 5(118~79kaB.P.)高分辨率的1δ8O记录。研究表明,万象洞石笋1δ8O值与夏季风强度呈负相关关系,与我国西南部的贵州董歌洞石笋1δ8O记录有良好的对应关系,并与高纬度的格陵兰NGR IP冰芯1δ8O记录和65°N太阳辐射强度有很好的一致性,说明万象洞石笋1δ8O记录了118~79kaB.P.期间亚洲季风强度的变化,同时也说明东亚季风强度的变化和全球气候变化同步,而且主要受控于北半球太阳辐射强度的变化。同时它与地中海碳酸盐记录有很好的相似性,和巴西石笋1δ8O记录在千年尺度上表现出相反的变化趋势,说明东亚季风区、地中海地区以及巴西季风区之间存在密切的联系,指示了南北半球气候在千年尺度上存在“跷跷板”(seesaw)现象。万象洞石笋1δ8O记录的M IS 5b与M IS 5 a突发性转换,与NGR IP冰芯1δ8O记录相似,而与神农架记录存在差异,说明万象洞地区对亚洲季风强度的响应更为敏感。展开更多
It is reported a multi-proxy palaeoclimatic study conducted on a MIS 5e calcarenite from the Mar Piccolo Basin(MP),Gulf of Taranto(GT)(Central Mediterranean).The calcarenite returned a rich malacofauna consisting of 1...It is reported a multi-proxy palaeoclimatic study conducted on a MIS 5e calcarenite from the Mar Piccolo Basin(MP),Gulf of Taranto(GT)(Central Mediterranean).The calcarenite returned a rich malacofauna consisting of 120 extant species,including four of the tropical Senegalese Fauna,today absent in the Mediterranean.The biogeographic-climatic affinity of the assemblage shows,compared to today,a double percentage of warm affinity species,while the cold affinity species are nearly equally represented,indicating a warmer but not strictly tropical SST.This is confirmed by the most recurring preferred SST ranges of the assemblage,indicating an average of 20℃.The skeletal compositions of five well-preserved molluscan and coral specimens were analyzed for trace elements and stable isotopes for further mean SST estimations.From the comparison of the results of several equations available in literature,it appears that only some SST estimations are realistic,converging into similar values of,on average,20.8±0.9℃.Considering all the used proxies,the MIS 5e SST difference compared to today falls in the range 1.2—2.0℃for the GT(being a more reasonable scenario)and 2.0—2.8℃for the MP.This is not a firmly tropical-like SST setting as suggested by the sole Senegalese fauna,indicating at least 2.7℃—3.5℃more than today’s GT and MP,respectively.The approximations and assumptions made for obtaining SST values with any single proxy indicate the need of a multi-proxy approach to define the best SST estimation.展开更多
The TMS5e sequence from the Tumen section, at the southern edge of Tengger Desert in the northwestern China, is synchronous with Marine Isotope Stage 5e （MIS5e）. It consists of 16 layers of aeolian dune sands, 11 la...The TMS5e sequence from the Tumen section, at the southern edge of Tengger Desert in the northwestern China, is synchronous with Marine Isotope Stage 5e （MIS5e）. It consists of 16 layers of aeolian dune sands, 11 layers of lacustrine loess-like facies, and 5 layers of lacustrine facies. The results of grain-size analysis shows that the pa- laeo-mobile dune sands, palaeo-fixed to semi-fixed dune sands and loess-like sandy loams are mainly composed of sands, ranging from 70% to 96%; their silt contents ranged from 4% to 20%, and their clay contents ranged from 1% to 5%; the climate under which the aeolian dune sands were deposited is similar to that under which modern mobile dune sands form, which is caused by the dominance of the cold, dry East Asian winter monsoon. In contrast, the lacustrine loess-like facies and lacustrine facies had a lower sand contents than those of the three aeolian dune sands, but have higher silt and clay contents, most of their sand content ranged from 30% to 60%, their silt contents ranged from 35% to 55%, and their clay contents ranged from 6% to 20%. The lacustrine loess-like facies and lacustrine facies formed under the influence of the warm, humid East Asian summer monsoon based on their similarity with modern sediments. The grain-size indicator Mz （mean grain diameter） and the SC/D value in the TMS5e sequence indicate climatic insta- bility at the southern edge of the Tengger Desert during MIS5e, with at least 14 fluctuations between a warm, humid climate and a cold, dry climate, divided into five stages： TMS5e5 （139 kyr to 129.3 kyr B.P.）, TMS5e4 （129.3 kyr to 124 kyr B.P.）, TMS5e3 （124 kyr to 119.5 kyr B.P.）, TMS5e2 （119.5 kyr to 116.5 kyr B.P.）, and TMS5el （116.5 kyr to 113.7 kyr B.P.）. These correspond roughly to MIS5e5, MIS5e4, MIS5e3, MIS5e2, and MIS5el, respectively, in the GRIP ice core data.展开更多
AIM To evaluate the levels of mi R-192-5 p in non-alcoholic fatty liver disease(NAFLD) models and demonstrate the role of mi R-192-5 p in lipid accumulation. METHODS Thirty Sprague Dawley rats were randomly divided in...AIM To evaluate the levels of mi R-192-5 p in non-alcoholic fatty liver disease(NAFLD) models and demonstrate the role of mi R-192-5 p in lipid accumulation. METHODS Thirty Sprague Dawley rats were randomly divided into three groups, which were given a standard diet, a high-fat diet(HFD), and an HFD with injection of liraglutide. At the end of 16 weeks, hepatic mi R-192-5 p and stearoyl-Co A desaturase 1(SCD-1) levels were measured. Mi R-192-5 p mimic and inhibitor and SCD-1 si RNA were transfected into Huh7 cells exposed to palmitic acid(PA). Lipid accumulation was evaluated by oil red O staining and triglyceride assays. Direct interaction was validated by dual-luciferase reporter gene assays.RESULTS The HFD rats showed a 0.46-fold decrease and a 3.5-fold increase in hepatic mi R-192-5 p and SCD-1 protein levels compared with controls, respectively, which could be reversed after disease remission by liraglutide injection(P < 0.01). The Huh7 cells exposed to PA also showed down-regulation and up-regulation of mi R-192-5 p and SCD-1 protein levels, respectively(P < 0.01). Transfection with mi R-192-5 p mimic and inhibitor in Huh7 cells induced dramatic repression and promotion of SCD-1 protein levels, respectively(P < 0.01). Luciferase activity was suppressed and enhanced by mi R-192-5 p mimic and inhibitor, respectively, in wild-type SCD-1(P < 0.01) but not in mutant SCD-1. Mi R-192-5 p overexpression reduced lipid accumulation significantly in PA-treated Huh7 cells, and SCD-1 si RNA transfection abrogated the lipid deposition aggravated by mi R-192-5 p inhibitor(P < 0.01).CONCLUSION This study demonstrates that mi R-192-5 p has a negative regulatory role in lipid synthesis, which is mediated through its direct regulation of SCD-1.展开更多
文摘位于青藏高原与黄土高原过渡带的甘肃武都万象洞石笋WXSM51和WXSM52提供了M IS 5(118~79kaB.P.)高分辨率的1δ8O记录。研究表明,万象洞石笋1δ8O值与夏季风强度呈负相关关系,与我国西南部的贵州董歌洞石笋1δ8O记录有良好的对应关系,并与高纬度的格陵兰NGR IP冰芯1δ8O记录和65°N太阳辐射强度有很好的一致性,说明万象洞石笋1δ8O记录了118~79kaB.P.期间亚洲季风强度的变化,同时也说明东亚季风强度的变化和全球气候变化同步,而且主要受控于北半球太阳辐射强度的变化。同时它与地中海碳酸盐记录有很好的相似性,和巴西石笋1δ8O记录在千年尺度上表现出相反的变化趋势,说明东亚季风区、地中海地区以及巴西季风区之间存在密切的联系,指示了南北半球气候在千年尺度上存在“跷跷板”(seesaw)现象。万象洞石笋1δ8O记录的M IS 5b与M IS 5 a突发性转换,与NGR IP冰芯1δ8O记录相似,而与神农架记录存在差异,说明万象洞地区对亚洲季风强度的响应更为敏感。
基金Financial support for this research derived from MIUR(ex 60%)funds(resp.E.Perri and S.Critelli)PON React-EU“Ricerca e Innovazione”2014—2020 funds(CUP:H25F21001220006)。
文摘It is reported a multi-proxy palaeoclimatic study conducted on a MIS 5e calcarenite from the Mar Piccolo Basin(MP),Gulf of Taranto(GT)(Central Mediterranean).The calcarenite returned a rich malacofauna consisting of 120 extant species,including four of the tropical Senegalese Fauna,today absent in the Mediterranean.The biogeographic-climatic affinity of the assemblage shows,compared to today,a double percentage of warm affinity species,while the cold affinity species are nearly equally represented,indicating a warmer but not strictly tropical SST.This is confirmed by the most recurring preferred SST ranges of the assemblage,indicating an average of 20℃.The skeletal compositions of five well-preserved molluscan and coral specimens were analyzed for trace elements and stable isotopes for further mean SST estimations.From the comparison of the results of several equations available in literature,it appears that only some SST estimations are realistic,converging into similar values of,on average,20.8±0.9℃.Considering all the used proxies,the MIS 5e SST difference compared to today falls in the range 1.2—2.0℃for the GT(being a more reasonable scenario)and 2.0—2.8℃for the MP.This is not a firmly tropical-like SST setting as suggested by the sole Senegalese fauna,indicating at least 2.7℃—3.5℃more than today’s GT and MP,respectively.The approximations and assumptions made for obtaining SST values with any single proxy indicate the need of a multi-proxy approach to define the best SST estimation.
基金Foundation item:Under the auspices of State Key Laboratory of Loess and Quaternary Geology,Institute of Earth Environment,Chinese Academy of Sciences (No.SKLLQG0901,SKLLQG1013)Research Fund for the Doctoral Program of Higher Education of China (No.20094407120004)
文摘The TMS5e sequence from the Tumen section, at the southern edge of Tengger Desert in the northwestern China, is synchronous with Marine Isotope Stage 5e （MIS5e）. It consists of 16 layers of aeolian dune sands, 11 layers of lacustrine loess-like facies, and 5 layers of lacustrine facies. The results of grain-size analysis shows that the pa- laeo-mobile dune sands, palaeo-fixed to semi-fixed dune sands and loess-like sandy loams are mainly composed of sands, ranging from 70% to 96%; their silt contents ranged from 4% to 20%, and their clay contents ranged from 1% to 5%; the climate under which the aeolian dune sands were deposited is similar to that under which modern mobile dune sands form, which is caused by the dominance of the cold, dry East Asian winter monsoon. In contrast, the lacustrine loess-like facies and lacustrine facies had a lower sand contents than those of the three aeolian dune sands, but have higher silt and clay contents, most of their sand content ranged from 30% to 60%, their silt contents ranged from 35% to 55%, and their clay contents ranged from 6% to 20%. The lacustrine loess-like facies and lacustrine facies formed under the influence of the warm, humid East Asian summer monsoon based on their similarity with modern sediments. The grain-size indicator Mz （mean grain diameter） and the SC/D value in the TMS5e sequence indicate climatic insta- bility at the southern edge of the Tengger Desert during MIS5e, with at least 14 fluctuations between a warm, humid climate and a cold, dry climate, divided into five stages： TMS5e5 （139 kyr to 129.3 kyr B.P.）, TMS5e4 （129.3 kyr to 124 kyr B.P.）, TMS5e3 （124 kyr to 119.5 kyr B.P.）, TMS5e2 （119.5 kyr to 116.5 kyr B.P.）, and TMS5el （116.5 kyr to 113.7 kyr B.P.）. These correspond roughly to MIS5e5, MIS5e4, MIS5e3, MIS5e2, and MIS5el, respectively, in the GRIP ice core data.
基金Supported by National Key R&D Program of China No.2017YFC0908900National Key Basic Research Project,No.2012CB517501National Natural Science Foundation of China,No.81470840 and No.81600464
文摘AIM To evaluate the levels of mi R-192-5 p in non-alcoholic fatty liver disease(NAFLD) models and demonstrate the role of mi R-192-5 p in lipid accumulation. METHODS Thirty Sprague Dawley rats were randomly divided into three groups, which were given a standard diet, a high-fat diet(HFD), and an HFD with injection of liraglutide. At the end of 16 weeks, hepatic mi R-192-5 p and stearoyl-Co A desaturase 1(SCD-1) levels were measured. Mi R-192-5 p mimic and inhibitor and SCD-1 si RNA were transfected into Huh7 cells exposed to palmitic acid(PA). Lipid accumulation was evaluated by oil red O staining and triglyceride assays. Direct interaction was validated by dual-luciferase reporter gene assays.RESULTS The HFD rats showed a 0.46-fold decrease and a 3.5-fold increase in hepatic mi R-192-5 p and SCD-1 protein levels compared with controls, respectively, which could be reversed after disease remission by liraglutide injection(P < 0.01). The Huh7 cells exposed to PA also showed down-regulation and up-regulation of mi R-192-5 p and SCD-1 protein levels, respectively(P < 0.01). Transfection with mi R-192-5 p mimic and inhibitor in Huh7 cells induced dramatic repression and promotion of SCD-1 protein levels, respectively(P < 0.01). Luciferase activity was suppressed and enhanced by mi R-192-5 p mimic and inhibitor, respectively, in wild-type SCD-1(P < 0.01) but not in mutant SCD-1. Mi R-192-5 p overexpression reduced lipid accumulation significantly in PA-treated Huh7 cells, and SCD-1 si RNA transfection abrogated the lipid deposition aggravated by mi R-192-5 p inhibitor(P < 0.01).CONCLUSION This study demonstrates that mi R-192-5 p has a negative regulatory role in lipid synthesis, which is mediated through its direct regulation of SCD-1.
