【目的】全球变暖背景下,喀斯特地貌广布的西南地区可能面临石漠化加剧的风险,对该区域石漠化演变历史的重建具有重要意义。【方法】通过采自贵州省黔西县黑洞一支石笋(HD12)的29个230Th年龄和954个δ^(13)C数据,重建了该地区过去4 750...【目的】全球变暖背景下,喀斯特地貌广布的西南地区可能面临石漠化加剧的风险,对该区域石漠化演变历史的重建具有重要意义。【方法】通过采自贵州省黔西县黑洞一支石笋(HD12)的29个230Th年龄和954个δ^(13)C数据,重建了该地区过去4 750年的生态环境演变历史。【结果与结论】发现在4 322~3 526 a B.P.以及803~82 a B.P.时段存在两个显著的δ^(13)C正偏移,说明这两个时段洞穴上方的生态环境出现了恶化。HD12石笋δ^(13)C记录在约803 a B.P.的显著偏正持续了约290 a,其振幅达4.2‰,指示了该区域石漠化的扩张过程。这一时期西南地区多个洞穴石笋δ^(13)C值的一致偏正特征,可能指示了宋末靖康事件(823 a B.P.)后,人口的大量迁入和气候的干旱化导致了该区域石漠化的扩张。HD12石笋δ^(13)C值在4 322~3 526 a B.P.时期的偏正,振幅达4.9‰,其中4 322~3 977 a B.P.偏正过程对应于北半球4.2 ka事件,而3 777~3 526 a B.P.的偏正对应3.7 ka事件,两个时期的干旱事件在西南地区的多个石笋与湖泊记录中均有体现,说明在此期间,亚洲夏季风减弱,降水减少可能引起了该区域植被覆盖度大幅降低和土壤严重退化。展开更多
Two new isomeric compounds of rare acyclic C13-norisoprenoids, along with two known lignans sauchinone and licarin A, were isolated from the herb of Saururus chinensis （Lour.） Baill. Their structures were elucidated...Two new isomeric compounds of rare acyclic C13-norisoprenoids, along with two known lignans sauchinone and licarin A, were isolated from the herb of Saururus chinensis （Lour.） Baill. Their structures were elucidated on the basis of spectral analysis.展开更多
Extracts of plant origin,particularly tannins,are attracting growing interest for the sustainable development of materials in the industrial sector.The discovery of new tannins is therefore necessary.The aim of this w...Extracts of plant origin,particularly tannins,are attracting growing interest for the sustainable development of materials in the industrial sector.The discovery of new tannins is therefore necessary.The aim of this work was to contribute to the understanding of the properties of Paraberlinia bifoliolata tannin by Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectroscopy MALDI-TOF/MS and Carbon 13 Nuclear Magnetic Resonance(13C NMR).The chemical composition of tannin extracted from Paraberlinia bifoliolata bark was determined,as was the mechanical strength of the resin hardened with Acacia nilotica extracts.Yield by successive water extraction was 35%.MALDI-TOF/MS analysis revealed the presence of three new compounds in this tannin,previously unknown in this family of extracts.These are 3-hydroxyproline acid,N-methyl-4-hydroxypipecolic acid and N-methyl-5-dihydroxypipecolic acid.The identification of the above molecules means that this tannin can be used for industrial applications,as a resin in the manufacture of particleboard and in the formulation of green corrosion inhibitors.This information is reinforced by 13C NMR spectrometry,which indicates the presence of several polyflavonoid units,confirming the condensed nature of the tannin.Thermomechanical analysis of the resin formed by the purified tannin of Paraberlinia bifoliolata to which a vegetal biohardener has been added provided a Modulus of Elasticity(MOE)value of 4840 MPa at 150℃,confirming its possible use as a binder resin in the manufacture of wood panels as well as for the formulation of a corrosion inhibitor.展开更多
Tree radial growth can have significantly differ-ent responses to climate change depending on the environ-ment.To elucidate the effects of climate on radial growth and stable carbon isotope(δ^(13)C)fractionation of Q...Tree radial growth can have significantly differ-ent responses to climate change depending on the environ-ment.To elucidate the effects of climate on radial growth and stable carbon isotope(δ^(13)C)fractionation of Qing-hai spruce(Picea crassifolia),a widely distributed native conifer in northwestern China in different environments,we developed chronologies for tree-ring widths and δ^(13)C in trees on the southern and northern slopes of the Qilian Mountains,and analysed the relationship between these tree-ring variables and major climatic factors.Tree-ring widths were strongly influenced by climatic factors early in the growing season,and the radial growth in trees on the northern slopes was more sensitive to climate than in trees on the southern.Tree-ring δ^(13)C was more sensitive to climate than radial growth.δ^(13)C fractionation was mainly influenced by summer temperature and precipitation early in the growing season.Stomatal conductance more strongly limited stable carbon isotope fractionation in tree rings than photosynthetic rate did.The response between tree rings and climate in mountains gradually weakened as climate warmed.Changes in radial growth and stable carbon isotope fractionation of P.crassifolia in response to climate in the Qilian Mountains may be further complicated by continued climate change.展开更多
目的探讨嗅觉受体家族13亚家族C成员2(olfactory receptor family 13 subfamily C member 2,OR13C2)在肝细胞癌(hepatocellular carcinoma,HCC)中的表达及临床病理意义。方法收集2017年8月至2022年3月于右江民族医学院附属医院进行手术...目的探讨嗅觉受体家族13亚家族C成员2(olfactory receptor family 13 subfamily C member 2,OR13C2)在肝细胞癌(hepatocellular carcinoma,HCC)中的表达及临床病理意义。方法收集2017年8月至2022年3月于右江民族医学院附属医院进行手术切除治疗的HCC患者为研究对象,取石蜡包埋的癌组织及癌旁非癌肝组织适量,采用免疫组化染色EnVision二步法检测OR13C2在上述组织中的表达情况,通过Logistic回归模型分析OR13C2的表达与HCC组织学分级、癌旁肝纤维化等临床病理特征的相关性。结果OR13C2在HCC癌组织中的表达明显低于癌旁肝组织,差异具有统计学意义(P<0.05);HCC肿瘤组织中OR13C2的表达与HCC组织学分级差异有统计学意义(P<0.05),HCC中OR13C2的表达与HCC的组织学分级呈负相关(r=-0.213,P<0.05),OR13C2表达下调为肿瘤去分化风险因子(风险值为3.914,P<0.05);OR13C2在癌组织中的表达与HCC的发病年龄、性别、包膜侵犯、临床分期、乙型肝炎病毒感染、术前血清甲胎蛋白及微血管侵犯以及癌组织中Glypican-3、Arginase-1表达的差异均无统计学意义(P>0.05),OR13C2在癌旁肝组织中的表达与肝纤维化分期、慢性肝炎分级差异无统计学意义(P>0.05)。结论HCC癌组织中OR13C2表达水平下调,这种下调与肿瘤的组织学分级负相关,是一个肿瘤去分化的风险因子。这些结果提示OR13C2表达失调在HCC发生中可能起一定的促进作用。展开更多
文摘【目的】全球变暖背景下,喀斯特地貌广布的西南地区可能面临石漠化加剧的风险,对该区域石漠化演变历史的重建具有重要意义。【方法】通过采自贵州省黔西县黑洞一支石笋(HD12)的29个230Th年龄和954个δ^(13)C数据,重建了该地区过去4 750年的生态环境演变历史。【结果与结论】发现在4 322~3 526 a B.P.以及803~82 a B.P.时段存在两个显著的δ^(13)C正偏移,说明这两个时段洞穴上方的生态环境出现了恶化。HD12石笋δ^(13)C记录在约803 a B.P.的显著偏正持续了约290 a,其振幅达4.2‰,指示了该区域石漠化的扩张过程。这一时期西南地区多个洞穴石笋δ^(13)C值的一致偏正特征,可能指示了宋末靖康事件(823 a B.P.)后,人口的大量迁入和气候的干旱化导致了该区域石漠化的扩张。HD12石笋δ^(13)C值在4 322~3 526 a B.P.时期的偏正,振幅达4.9‰,其中4 322~3 977 a B.P.偏正过程对应于北半球4.2 ka事件,而3 777~3 526 a B.P.的偏正对应3.7 ka事件,两个时期的干旱事件在西南地区的多个石笋与湖泊记录中均有体现,说明在此期间,亚洲夏季风减弱,降水减少可能引起了该区域植被覆盖度大幅降低和土壤严重退化。
文摘Two new isomeric compounds of rare acyclic C13-norisoprenoids, along with two known lignans sauchinone and licarin A, were isolated from the herb of Saururus chinensis （Lour.） Baill. Their structures were elucidated on the basis of spectral analysis.
基金supported by the Institut de la Francophonie pour le Developpement Durable(IFDD/Canada)/Projet de Deploiement des Technologies et Innovations Environnementales(PDTIE)funded by Organisation Internationale de la Francophonie(OIF)the Organisation of African,Caribbean and Pacific States and the European Union(EU)(FED/220/421-370)the Local Materials Promotion Authority(MIPROMALO)of the Ministry of Scientific Research and Innovation of Cameroon who made it possible for this scientific work to be carried out.
文摘Extracts of plant origin,particularly tannins,are attracting growing interest for the sustainable development of materials in the industrial sector.The discovery of new tannins is therefore necessary.The aim of this work was to contribute to the understanding of the properties of Paraberlinia bifoliolata tannin by Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectroscopy MALDI-TOF/MS and Carbon 13 Nuclear Magnetic Resonance(13C NMR).The chemical composition of tannin extracted from Paraberlinia bifoliolata bark was determined,as was the mechanical strength of the resin hardened with Acacia nilotica extracts.Yield by successive water extraction was 35%.MALDI-TOF/MS analysis revealed the presence of three new compounds in this tannin,previously unknown in this family of extracts.These are 3-hydroxyproline acid,N-methyl-4-hydroxypipecolic acid and N-methyl-5-dihydroxypipecolic acid.The identification of the above molecules means that this tannin can be used for industrial applications,as a resin in the manufacture of particleboard and in the formulation of green corrosion inhibitors.This information is reinforced by 13C NMR spectrometry,which indicates the presence of several polyflavonoid units,confirming the condensed nature of the tannin.Thermomechanical analysis of the resin formed by the purified tannin of Paraberlinia bifoliolata to which a vegetal biohardener has been added provided a Modulus of Elasticity(MOE)value of 4840 MPa at 150℃,confirming its possible use as a binder resin in the manufacture of wood panels as well as for the formulation of a corrosion inhibitor.
基金supported by Basic Research Operating Expenses of the Central level Non-profit Research Institutes (IDM2022003)National Natural Science Foundation of China (42375054)+2 种基金Regional collaborative innovation project of Xinjiang (2021E01022,2022E01045)Young Meteorological Talent Program of China Meteorological Administration,Tianshan Talent Program of Xinjiang (2022TSYCCX0003)Youth Innovation Team of China Meteorological Administration (CMA2023QN08).
文摘Tree radial growth can have significantly differ-ent responses to climate change depending on the environ-ment.To elucidate the effects of climate on radial growth and stable carbon isotope(δ^(13)C)fractionation of Qing-hai spruce(Picea crassifolia),a widely distributed native conifer in northwestern China in different environments,we developed chronologies for tree-ring widths and δ^(13)C in trees on the southern and northern slopes of the Qilian Mountains,and analysed the relationship between these tree-ring variables and major climatic factors.Tree-ring widths were strongly influenced by climatic factors early in the growing season,and the radial growth in trees on the northern slopes was more sensitive to climate than in trees on the southern.Tree-ring δ^(13)C was more sensitive to climate than radial growth.δ^(13)C fractionation was mainly influenced by summer temperature and precipitation early in the growing season.Stomatal conductance more strongly limited stable carbon isotope fractionation in tree rings than photosynthetic rate did.The response between tree rings and climate in mountains gradually weakened as climate warmed.Changes in radial growth and stable carbon isotope fractionation of P.crassifolia in response to climate in the Qilian Mountains may be further complicated by continued climate change.
文摘目的探讨嗅觉受体家族13亚家族C成员2(olfactory receptor family 13 subfamily C member 2,OR13C2)在肝细胞癌(hepatocellular carcinoma,HCC)中的表达及临床病理意义。方法收集2017年8月至2022年3月于右江民族医学院附属医院进行手术切除治疗的HCC患者为研究对象,取石蜡包埋的癌组织及癌旁非癌肝组织适量,采用免疫组化染色EnVision二步法检测OR13C2在上述组织中的表达情况,通过Logistic回归模型分析OR13C2的表达与HCC组织学分级、癌旁肝纤维化等临床病理特征的相关性。结果OR13C2在HCC癌组织中的表达明显低于癌旁肝组织,差异具有统计学意义(P<0.05);HCC肿瘤组织中OR13C2的表达与HCC组织学分级差异有统计学意义(P<0.05),HCC中OR13C2的表达与HCC的组织学分级呈负相关(r=-0.213,P<0.05),OR13C2表达下调为肿瘤去分化风险因子(风险值为3.914,P<0.05);OR13C2在癌组织中的表达与HCC的发病年龄、性别、包膜侵犯、临床分期、乙型肝炎病毒感染、术前血清甲胎蛋白及微血管侵犯以及癌组织中Glypican-3、Arginase-1表达的差异均无统计学意义(P>0.05),OR13C2在癌旁肝组织中的表达与肝纤维化分期、慢性肝炎分级差异无统计学意义(P>0.05)。结论HCC癌组织中OR13C2表达水平下调,这种下调与肿瘤的组织学分级负相关,是一个肿瘤去分化的风险因子。这些结果提示OR13C2表达失调在HCC发生中可能起一定的促进作用。
