| 1 | Multiphase microstructure formation and its effect on fracture behavior of medium carbon high silicon high strength steel显示文摘This work investigated the evolution of multiphase microstructure and impact fracture behavior of medium carbon high silicon high strength steel subjected to the austempering treatment at 240,360,and400℃.The results show that martensite,bainite,and retained austenite(RA)are the main microstructural phases.The austempering treatments at 360 and 400℃ caused the formation of carbon-poor ferrite in the matrix,and the transformation of ultrafine bainite into coarse lath bainite and granular bainite,respectively.Thick filmy RA was distributed between bainite laths.The polygonal martensiteaustenite islands and blocky RA formed along the grain boundaries.The average carbon concentration in the matrix decreased with the temperature increase,while the impact toughness initially increased and then dropped with temperature.The quasi-cleavage brittle fracture dominated the impact fracture mechanism of the sample austempered at 240℃ by forming tearing surfaces and tearing steps.The microcracks disappeared in the RA on the prior austenite grain boundaries.On the other side,the fracture surface of the sample austempered at 360℃ exhibited ductile fracture with deep dimples and brittle fracture with cleavage river patterns.The polygonal martensite-austenite islands or blocky RA constrained the microcracks.After austempered at 400℃,the brittle fracture was dominant,showing river patterns,and the microcracks propagated through the granular bainite without any resistance. | Kui Chen Huabing Li Zhouhua Jiang Fubin Liu Congpeng Kang Xiaodong Ma Baojun Zhao | 2021 | Journal of Materials Science & Technology2021，，13： | 3 |
| 4 | Investigation on the Metabolism of Salvianolic acid B, Tanshinone Ⅱ A, Ginsenoside Rg1 and Ginsenoside Rb1 from Danshen-Sanqi Herbal Pair in Zebrafish by Liquid Chromatography-Tandem Mass Spectrometry Analysis显示文摘Background:Salvianolic acid B(SAB),tanshinone IIA(TIIA),ginsenoside Rg1(GRg1)and ginsenoside Rb1(GRb1)are the main active components of Danshen-Sanqi herbal pair(DS-SQ),which is widely used in the treatment of cardiovascular diseases in Asia.The compatibility mechanisms of compound Chinese herbal preparation may be clarified to some degree by understanding the interactions of the active components based on their metabolic research.Furthermore,zebrafish is a convenient and feasible model to study the metabolism of drugs.Objective:To investigate the metabolism of SAB,TIIA,GRg1 and GRb1 in zebrafish by liquid chromatography-tandem mass spectrometry(LC-MS/MS)analysis.Methods:Zebrafish embryos after 48-hour hatching were divided into nine experimental groups.The blank group was exposed to 1 mL ultra-pure water.Eight drug-treated groups were exposed to 1 mL solution of SAB,TIIA,GRg1,GRb1,SAB and GRg1,SAB and GRb1,TIIA and GRg1,TIIA and GRb1,respectively.After homogenization,they were analyzed by LC-MS/MS.The Structures of the metabolites were determined by analyzing their corre-sponding mass spectra information and comparing the data with relevant literature.According to the change of the amount of metabolites,the metabolic effect between SAB,TIIA,GRg1 and GRb1 were investigated.Results:Eighteen metabolites and four parent drugs of SAB,TIIA,GRg1 and GRb1 in zebrafish were identified by LC-MS/MS,including methylation,degradation,reduction,dehydrogenation,hydroxylation,desugarization and glucuronidation metabolites.Furthermore,after being combined exposed of drugs,GRg1 and GRb1 could promote the metabolism of TIIA,while SAB and TIIA could promote the metabolism of GRg1 and GRb1 to different degree.Conclusion:By using LC-MS/MS analysis,zebrafish was successfully applied to study the metabolism of SAB,TIIA,GRg1 and GRb1,which is significance to explain the possible synergistic effect of components in DS-SQ through modifying the metabolism in zebrafish.This study can be helpful for the further research of DS-SQ. | Shijun Yin Congpeng Zhao Guang Hu Hua Chen Fengqing Yang | 2021 | Clinical Complementary Medicine and Pharmacology2021，1，1： | 0 |
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