Selective laser melting(SLM)has become a critical technique for manufacturing molds with conformal cooling channels to achieve high cooling efficiencies.A novel selective laser-melted 718HH plastic mold steel with an ...Selective laser melting(SLM)has become a critical technique for manufacturing molds with conformal cooling channels to achieve high cooling efficiencies.A novel selective laser-melted 718HH plastic mold steel with an excellent combination of strength and toughness was investigated.After SLM fabrication,quenching and tempering are conducted as post-printing heat treatment(PPHT)to improve the mechanical properties of the as-built samples.Both the microstructure and the corresponding mechanical properties were systematically studied.The results show that PPHT facilitates the complete martensite transformation.Meanwhile,the retained austenite(γ)phase was still found in the as-built samples.And high-density dislocations were dispersively distributed within the martensite matrix for both as-built and as-PPHTed samples.After PPHT,due to the recovery and recrystallization of martensite,reduced dislocation density and increased high-angle grain boundaries,the microhardness of the as-built samples decreased from 498.8±16.7 to 382.1±5.0 HV0.3.Correspondingly,the strength,including the ultimate tensile strength and yield strength,of the as-built and as-PPHTed samples also decreased from 1411.3±17.8 to 1208.7±3.2 MPa and 1267.3±11.7 to 1084.7±5.1 MPa,respectively.On the contrary,the value of impact energy significantly increased from 15.3±1.2 J(as-built)to 39.7±1.2 J(as-PPHTed).Notably,the mechanical properties of SLMed 718HH samples are significantly better than those of corresponding wrought samples.展开更多
目的:研究HH胶囊体外抗乙型肝炎病毒的作用及其对抗病毒蛋白2'5'-寡腺苷酸合成酶(2'5'-Oligoadenylate Synthetase,2'5'-OAS)、RAN依赖蛋白激酶(RAN-dependent protein kinase,PKR)的影响.方法:HepG2.2.15是目...目的:研究HH胶囊体外抗乙型肝炎病毒的作用及其对抗病毒蛋白2'5'-寡腺苷酸合成酶(2'5'-Oligoadenylate Synthetase,2'5'-OAS)、RAN依赖蛋白激酶(RAN-dependent protein kinase,PKR)的影响.方法:HepG2.2.15是目前最常用的乙型肝炎病毒感染的体外实验模型,将细胞随机分为空白对照组、阳性对照组(3TC)、不同浓度的HH胶囊组.用CCK-8检测药物细胞毒性,酶联免疫法检测乙型肝炎病毒表面抗原(HBsAg)和乙型肝炎病毒e抗原(HBeAg);荧光定量聚合酶链反应法检测乙型肝炎病毒脱氧核糖核酸(HBVDNA);用Westernblot、荧光定量PCR方法分别检测细胞内抗病毒蛋白2'5'-OAS、PKR及其mRNA水平.结果:HH胶囊的TC50是2.11g/L、312.00mg/L、156.00mg/L、78.00mg/L、39.00mg/LHH胶囊均可以降低细胞外HBeAg(0.285±0.007,0.462±0.008,0.565±0.009,0.733±0.008vs1.334±0.007)和HbsAg(0.834±0.008,1.021±0.011,1.347±0.017,1.548±0.015vs2.593±0.008)水平,312.00mg/L、156.00mg/LHH胶囊均可以减低细胞内乙型肝炎病毒DNA[(3.423±0.110)×109copies/L,(3.640±0.082)×109copies/Lvs(6.857±0.060)×109copies/L]、细胞外乙型肝炎病毒DNA(6547±87、7710±62vs24300±200),312.00mg/LHH胶囊可以增加细胞内OASmRNA(0.885±0.038vs0.688±0.068)、PKRmRNA(0.139±0.06vs0.058±0.005)表达及其OAS、PKR蛋白水平.结论:HH胶囊具有良好的抗乙型肝炎病毒作用,推测可能与增加细胞内OAS、PKR及其mRNA水平有关.展开更多
【目的】用生防菌Hhs.015发酵液处理苹果发病枝条,研究其对树体微生态的影响。【方法】采用改良CTAB法提取样本中的总DNA,对细菌群落的16S r DNA的V4+V5区进行高通量测序,研究发病枝条涂抹Hhs.015菌悬液30 d后树皮内细菌区系组成变化,...【目的】用生防菌Hhs.015发酵液处理苹果发病枝条,研究其对树体微生态的影响。【方法】采用改良CTAB法提取样本中的总DNA,对细菌群落的16S r DNA的V4+V5区进行高通量测序,研究发病枝条涂抹Hhs.015菌悬液30 d后树皮内细菌区系组成变化,分析其相对丰度以及多样性指标。【结果】在属水平上,生防菌处理样本与对照样本中的细菌种类显现出明显差异,生防菌处理组Gluconobacter丰度明显升高,放线菌门菌株丰度高于对照组,Burkholderia和Luteibacter等可能与致病相关的菌属丰度大幅下降。刮去外皮后取样,糖丝菌属(Saccharothrix)丰度仍处于较高水平。【结论】Hhs.015能够在苹果树皮内定殖,并影响苹果枝条皮层细菌区系。展开更多
目的建立HH胶囊的高效液相色谱(HPLC)指纹图谱,并观察HH胶囊的抗乙肝病毒(Hepatitis B virus,HBV)疗效。方法采用大连依利特ODS-BP C18色谱柱对HH胶囊的HPLC指纹图谱研究。HBV转基因小鼠随机分4组,苦参素组小鼠给予同体积含150mg/(kg...目的建立HH胶囊的高效液相色谱(HPLC)指纹图谱,并观察HH胶囊的抗乙肝病毒(Hepatitis B virus,HBV)疗效。方法采用大连依利特ODS-BP C18色谱柱对HH胶囊的HPLC指纹图谱研究。HBV转基因小鼠随机分4组,苦参素组小鼠给予同体积含150mg/(kg·d)苦参素混悬液,高、低剂量HH胶囊组小鼠分别给予同体积含7,2g/(kg·d)HH混悬液,5周后,Elisa法检测血清及肝组织HBs Ag,荧光定量PCR法检测血清及肝组织HBVDNA。结果标定14个特征峰构成HH胶囊的指纹图谱,确定其中1号峰为没食子酸、8号峰为柯里拉京、9号峰为虎杖苷、10号峰为鞣花酸、13号峰为甘草酸、14号峰为齐墩果酸。高剂量HH胶囊[7g/(kg·d)]可以显著降低HBV转基因小鼠肝脏和血清中的HBs Ag、HBVDNA水平,差异具有统计学意义(P<0.01、P<0.05),与苦参素组比较差异无统计学意义(P>0.05)。结论 HH胶囊具有确切的抗HBV作用,HPLC法对HH胶囊质量控制可靠。展开更多
基金financially supported by the National Key Research and Development Program of China(No.2021YFB3702501)the National Science and Technology Major Project(J2019-VI-0019-0134).
文摘Selective laser melting(SLM)has become a critical technique for manufacturing molds with conformal cooling channels to achieve high cooling efficiencies.A novel selective laser-melted 718HH plastic mold steel with an excellent combination of strength and toughness was investigated.After SLM fabrication,quenching and tempering are conducted as post-printing heat treatment(PPHT)to improve the mechanical properties of the as-built samples.Both the microstructure and the corresponding mechanical properties were systematically studied.The results show that PPHT facilitates the complete martensite transformation.Meanwhile,the retained austenite(γ)phase was still found in the as-built samples.And high-density dislocations were dispersively distributed within the martensite matrix for both as-built and as-PPHTed samples.After PPHT,due to the recovery and recrystallization of martensite,reduced dislocation density and increased high-angle grain boundaries,the microhardness of the as-built samples decreased from 498.8±16.7 to 382.1±5.0 HV0.3.Correspondingly,the strength,including the ultimate tensile strength and yield strength,of the as-built and as-PPHTed samples also decreased from 1411.3±17.8 to 1208.7±3.2 MPa and 1267.3±11.7 to 1084.7±5.1 MPa,respectively.On the contrary,the value of impact energy significantly increased from 15.3±1.2 J(as-built)to 39.7±1.2 J(as-PPHTed).Notably,the mechanical properties of SLMed 718HH samples are significantly better than those of corresponding wrought samples.
文摘目的:研究HH胶囊体外抗乙型肝炎病毒的作用及其对抗病毒蛋白2'5'-寡腺苷酸合成酶(2'5'-Oligoadenylate Synthetase,2'5'-OAS)、RAN依赖蛋白激酶(RAN-dependent protein kinase,PKR)的影响.方法:HepG2.2.15是目前最常用的乙型肝炎病毒感染的体外实验模型,将细胞随机分为空白对照组、阳性对照组(3TC)、不同浓度的HH胶囊组.用CCK-8检测药物细胞毒性,酶联免疫法检测乙型肝炎病毒表面抗原(HBsAg)和乙型肝炎病毒e抗原(HBeAg);荧光定量聚合酶链反应法检测乙型肝炎病毒脱氧核糖核酸(HBVDNA);用Westernblot、荧光定量PCR方法分别检测细胞内抗病毒蛋白2'5'-OAS、PKR及其mRNA水平.结果:HH胶囊的TC50是2.11g/L、312.00mg/L、156.00mg/L、78.00mg/L、39.00mg/LHH胶囊均可以降低细胞外HBeAg(0.285±0.007,0.462±0.008,0.565±0.009,0.733±0.008vs1.334±0.007)和HbsAg(0.834±0.008,1.021±0.011,1.347±0.017,1.548±0.015vs2.593±0.008)水平,312.00mg/L、156.00mg/LHH胶囊均可以减低细胞内乙型肝炎病毒DNA[(3.423±0.110)×109copies/L,(3.640±0.082)×109copies/Lvs(6.857±0.060)×109copies/L]、细胞外乙型肝炎病毒DNA(6547±87、7710±62vs24300±200),312.00mg/LHH胶囊可以增加细胞内OASmRNA(0.885±0.038vs0.688±0.068)、PKRmRNA(0.139±0.06vs0.058±0.005)表达及其OAS、PKR蛋白水平.结论:HH胶囊具有良好的抗乙型肝炎病毒作用,推测可能与增加细胞内OAS、PKR及其mRNA水平有关.
文摘【目的】用生防菌Hhs.015发酵液处理苹果发病枝条,研究其对树体微生态的影响。【方法】采用改良CTAB法提取样本中的总DNA,对细菌群落的16S r DNA的V4+V5区进行高通量测序,研究发病枝条涂抹Hhs.015菌悬液30 d后树皮内细菌区系组成变化,分析其相对丰度以及多样性指标。【结果】在属水平上,生防菌处理样本与对照样本中的细菌种类显现出明显差异,生防菌处理组Gluconobacter丰度明显升高,放线菌门菌株丰度高于对照组,Burkholderia和Luteibacter等可能与致病相关的菌属丰度大幅下降。刮去外皮后取样,糖丝菌属(Saccharothrix)丰度仍处于较高水平。【结论】Hhs.015能够在苹果树皮内定殖,并影响苹果枝条皮层细菌区系。
