A long-term experiment beginning in 1981 in Jinxian County of Jiangxi Province, subtropical China, was conducted in a paddy field under a double rice cropping system with four different fertilization regimes, includin...A long-term experiment beginning in 1981 in Jinxian County of Jiangxi Province, subtropical China, was conducted in a paddy field under a double rice cropping system with four different fertilization regimes, including 1) no fertilizer as control (CK), 2) balanced chemical N, P, and K fertilizers (NPK), 3) organic manure using milk vetch and pig manure in the early and late rice growing season, respectively (OM), and 4) balanced chemical fertilizers combined with organic manure (NPKM). Samples (0-17 cm) of the paddy field soil, which was derived from Quaternary red clay, were collected after the late rice harvest in November 2003 for determination of total organic carbon (TOC) and total nitrogen (TN) and fractions of organic C and N. Results showed that TOC and TN in the NPKM and OM treatments were significantly higher than those in other two treatments (CK and NPK). Application of organic manure with or without chemical fertilizers significantly increased the contents of all fractions of organic C and N, whereas chemical fertilizer application only increased the contents of occluded particulate organic C (oPOC) and amino acid N. In addition, application of organic manure significantly enhanced the proportions of free particulate organic carbon (fPOC) and oPOC in total C, and those of amino sugar N and amino acid N (P < 0.01) in total N. In contrast, chemical fertilizer application only increased the proportions of oPOC and amino acid N (P < 0.05). There were no significant differences in either contents or proportions of soil organic C and organic N fractions between the NPKM and OM treatments. These indicated that organic manure application with or without chemical fertilizers played the most significant role in enhancing soil organic C and N quantity and quality in the paddy field studied.展开更多
The characteristics of heavy precipitation occurrence in autumn（the month of September） over North China are investigated using daily observational data.Results indicate that heavy precipitation events experienced a...The characteristics of heavy precipitation occurrence in autumn（the month of September） over North China are investigated using daily observational data.Results indicate that heavy precipitation events experienced a significant decadal increase in 2000/2001.Further investigation reveals a close connection between heavy precipitation occurrence and simultaneous North Pacific SST.The SST anomaly over the North Pacific can result in intensification of the western North Pacific subtropical high and increased water vapor transport from the tropical ocean,which benefits the occurrence of heavy precipitation over North China.However,the key region of North Pacific SST influencing heavy precipitation events over North China was different in the periods 1960-2000 and 2001-2014,being located over the eastern Ocean to China in the first period but more eastward in the second period.This drift in the key region of SST is partly responsible for the decadal increase in heavy precipitation events over North China since 2000/2001.Additionally,the changes in SST variability（a decrease in the eastern Ocean to China and an increase to its east） may have been the main reason for the eastward movement of the key region in the latter period.Certainly,more work is needed in the future to verify the findings of this study.展开更多
目的通过多肽组学分析,从子宫内膜癌组织中筛选获得具有潜在生物学活性的内源性多肽。方法收集3例子宫内膜样腺癌组织标本(以3例年龄匹配的健康女性子宫内膜样本为对照),通过液相色谱-串联质谱法(liquid chromatography-tandem mass spe...目的通过多肽组学分析,从子宫内膜癌组织中筛选获得具有潜在生物学活性的内源性多肽。方法收集3例子宫内膜样腺癌组织标本(以3例年龄匹配的健康女性子宫内膜样本为对照),通过液相色谱-串联质谱法(liquid chromatography-tandem mass spectrometry,LC-MS/MS)获得子宫内膜癌特异性内源性多肽,借助生物信息学方法筛选具有潜在活性的功能多肽,使用CCK-8实验、Transwell及划痕实验验证多肽对子宫内膜癌细胞株HEC-1-A增殖、侵袭、迁移的影响,并以PCR、Western Blot方法选择性观察多肽对Wnt/β-catenin/EMT通路相关分子表达的影响。结果鉴定获得序列为TAGNVLMH的多肽(PDAEP-1)对应前体为SLC38A10,其表达水平与子宫内膜癌患者5年生存率相关;该多肽对子宫内膜癌细胞的增殖、侵袭、迁移有明显的抑制作用,且作用后Vimentin、β-catenin两者的mRNA及蛋白水平均显著降低,而E-cadherin则上调。结论通过调变Wnt/β-catenin/EMT通路相关分子,内源性多肽PDAEP-1在体外有抑制子宫内膜癌细胞增殖、侵袭和迁移的抗肿瘤活性,具有潜在的诊疗应用价值。展开更多
在江苏省黄河故道低肥力土壤条件下,探究有机肥替代化肥对小麦玉米和水稻小麦轮作体系中作物产量及土壤养分的影响,以明确低肥力土壤中有机肥替代化肥的规律和潜力。田间试验于2017年10月布置,设置6个不同处理,分别为不施肥(CK)、常量化...在江苏省黄河故道低肥力土壤条件下,探究有机肥替代化肥对小麦玉米和水稻小麦轮作体系中作物产量及土壤养分的影响,以明确低肥力土壤中有机肥替代化肥的规律和潜力。田间试验于2017年10月布置,设置6个不同处理,分别为不施肥(CK)、常量化肥(F)、常量化肥+40%有机肥(FM 0.4)、NPK总养分相等情况下分别用有机肥替代20%(F 0.8 M 0.2)、40%(F 0.6 M 0.4)及60%(F 0.4 M 0.6)化肥。结果表明:(1)小麦玉米轮作体系中,有机肥替代化肥在小麦季产量明显降低,其中有机肥替代60%化肥时,小麦产量显著降低而在玉米季产量无显著差异。在水稻小麦轮作体系中,不同比例有机肥替代化肥对作物产量的影响不显著。(2)施肥提升了小麦玉米和水稻小麦轮作体系中土壤有机质含量,小麦玉米轮作体系中土壤有机质提升8.07%~36.61%,水稻小麦轮作体系土壤有机质提升7.69%~40.22%。随着有机肥替代比例的增加,小麦玉米轮作体系中土壤全氮及速效钾含量呈降低趋势,而土壤磷素及碱解氮含量逐渐升高;水稻小麦轮作体系中土壤全氮含量逐渐降低,土壤全磷、碱解氮、速效钾含量逐渐升高。(3)相关性分析结果表明,作物产量与土壤全氮、碱解氮及速效磷含量均呈显著或极显著的正相关关系。综上所述,黄河故道地区由于基础地力较低,有机肥替代化肥并未表现出对作物的增产作用,但有机肥的投入有效地改善了土壤的养分状况,因此该区低肥力土壤在作物栽培中应当维持化肥用量并增施有机肥,以提升耕地质量。展开更多
基金Project supported by the National Natural Science Foundation of China (No. 30571094)the New Century Excellent Talents in University of China (No. NCET-05-0492)the Eleventh Five-Year Plan of China (Nos. 2006BAD15B02 and 2006BAD02A15)
文摘A long-term experiment beginning in 1981 in Jinxian County of Jiangxi Province, subtropical China, was conducted in a paddy field under a double rice cropping system with four different fertilization regimes, including 1) no fertilizer as control (CK), 2) balanced chemical N, P, and K fertilizers (NPK), 3) organic manure using milk vetch and pig manure in the early and late rice growing season, respectively (OM), and 4) balanced chemical fertilizers combined with organic manure (NPKM). Samples (0-17 cm) of the paddy field soil, which was derived from Quaternary red clay, were collected after the late rice harvest in November 2003 for determination of total organic carbon (TOC) and total nitrogen (TN) and fractions of organic C and N. Results showed that TOC and TN in the NPKM and OM treatments were significantly higher than those in other two treatments (CK and NPK). Application of organic manure with or without chemical fertilizers significantly increased the contents of all fractions of organic C and N, whereas chemical fertilizer application only increased the contents of occluded particulate organic C (oPOC) and amino acid N. In addition, application of organic manure significantly enhanced the proportions of free particulate organic carbon (fPOC) and oPOC in total C, and those of amino sugar N and amino acid N (P < 0.01) in total N. In contrast, chemical fertilizer application only increased the proportions of oPOC and amino acid N (P < 0.05). There were no significant differences in either contents or proportions of soil organic C and organic N fractions between the NPKM and OM treatments. These indicated that organic manure application with or without chemical fertilizers played the most significant role in enhancing soil organic C and N quantity and quality in the paddy field studied.
基金jointly supported by the National Natural Science Foundation of China[grant numbers 41305061 and41210007]the CAS-PKU(Chinese Academy of Sciences-Peking University)Joint Research Program
文摘The characteristics of heavy precipitation occurrence in autumn（the month of September） over North China are investigated using daily observational data.Results indicate that heavy precipitation events experienced a significant decadal increase in 2000/2001.Further investigation reveals a close connection between heavy precipitation occurrence and simultaneous North Pacific SST.The SST anomaly over the North Pacific can result in intensification of the western North Pacific subtropical high and increased water vapor transport from the tropical ocean,which benefits the occurrence of heavy precipitation over North China.However,the key region of North Pacific SST influencing heavy precipitation events over North China was different in the periods 1960-2000 and 2001-2014,being located over the eastern Ocean to China in the first period but more eastward in the second period.This drift in the key region of SST is partly responsible for the decadal increase in heavy precipitation events over North China since 2000/2001.Additionally,the changes in SST variability（a decrease in the eastern Ocean to China and an increase to its east） may have been the main reason for the eastward movement of the key region in the latter period.Certainly,more work is needed in the future to verify the findings of this study.
文摘目的通过多肽组学分析,从子宫内膜癌组织中筛选获得具有潜在生物学活性的内源性多肽。方法收集3例子宫内膜样腺癌组织标本(以3例年龄匹配的健康女性子宫内膜样本为对照),通过液相色谱-串联质谱法(liquid chromatography-tandem mass spectrometry,LC-MS/MS)获得子宫内膜癌特异性内源性多肽,借助生物信息学方法筛选具有潜在活性的功能多肽,使用CCK-8实验、Transwell及划痕实验验证多肽对子宫内膜癌细胞株HEC-1-A增殖、侵袭、迁移的影响,并以PCR、Western Blot方法选择性观察多肽对Wnt/β-catenin/EMT通路相关分子表达的影响。结果鉴定获得序列为TAGNVLMH的多肽(PDAEP-1)对应前体为SLC38A10,其表达水平与子宫内膜癌患者5年生存率相关;该多肽对子宫内膜癌细胞的增殖、侵袭、迁移有明显的抑制作用,且作用后Vimentin、β-catenin两者的mRNA及蛋白水平均显著降低,而E-cadherin则上调。结论通过调变Wnt/β-catenin/EMT通路相关分子,内源性多肽PDAEP-1在体外有抑制子宫内膜癌细胞增殖、侵袭和迁移的抗肿瘤活性,具有潜在的诊疗应用价值。
文摘在江苏省黄河故道低肥力土壤条件下,探究有机肥替代化肥对小麦玉米和水稻小麦轮作体系中作物产量及土壤养分的影响,以明确低肥力土壤中有机肥替代化肥的规律和潜力。田间试验于2017年10月布置,设置6个不同处理,分别为不施肥(CK)、常量化肥(F)、常量化肥+40%有机肥(FM 0.4)、NPK总养分相等情况下分别用有机肥替代20%(F 0.8 M 0.2)、40%(F 0.6 M 0.4)及60%(F 0.4 M 0.6)化肥。结果表明:(1)小麦玉米轮作体系中,有机肥替代化肥在小麦季产量明显降低,其中有机肥替代60%化肥时,小麦产量显著降低而在玉米季产量无显著差异。在水稻小麦轮作体系中,不同比例有机肥替代化肥对作物产量的影响不显著。(2)施肥提升了小麦玉米和水稻小麦轮作体系中土壤有机质含量,小麦玉米轮作体系中土壤有机质提升8.07%~36.61%,水稻小麦轮作体系土壤有机质提升7.69%~40.22%。随着有机肥替代比例的增加,小麦玉米轮作体系中土壤全氮及速效钾含量呈降低趋势,而土壤磷素及碱解氮含量逐渐升高;水稻小麦轮作体系中土壤全氮含量逐渐降低,土壤全磷、碱解氮、速效钾含量逐渐升高。(3)相关性分析结果表明,作物产量与土壤全氮、碱解氮及速效磷含量均呈显著或极显著的正相关关系。综上所述,黄河故道地区由于基础地力较低,有机肥替代化肥并未表现出对作物的增产作用,但有机肥的投入有效地改善了土壤的养分状况,因此该区低肥力土壤在作物栽培中应当维持化肥用量并增施有机肥,以提升耕地质量。
