Objective This work examines the impact of external electric fields at terahertz(THz)frequencies on doublestranded deoxyribonucleic acid(dsDNA)systems adsorbed on Au(111)surfaces in aqueous environments.Methods The in...Objective This work examines the impact of external electric fields at terahertz(THz)frequencies on doublestranded deoxyribonucleic acid(dsDNA)systems adsorbed on Au(111)surfaces in aqueous environments.Methods The investigation utilizes a molecular dynamics(MD)approach at the atomic level and vibrational dynamics calculations using the GolDNA-Amber force field.Results The results reveal that the sugar-phosphate backbone of the DNA exhibits reduced adherence to the gold surface,while the side chains display a stronger affinity.When subjecting the hydrated DNA strands to an electric field with frequencies up to 10 THz,peak intensities of vibrational dynamic density(VDoS)are observed at five different frequencies.Moreover,the strong electric field causes hydrogen bonds in the DNA within the slit to break.The sensitivity to the electric field is particularly pronounced at 8.8 THz and 9.6 THz,with different vibrational modes observed at varying electric field strengths.Conclusion These findings contribute to an enhanced understanding of the molecular organization of gold-plated charged biological interfaces.展开更多
为探讨低压静电场(low voltage electrostatic field,LVEF)处理对蝴蝶兰切花保鲜效果的影响,该研究以蝴蝶兰切花品种“天堂鸟”为试验对象,探究了低压静电场处理对蝴蝶兰切花瓶插期间观赏品质、理化指标及相关酶活性的变化,并通过低场...为探讨低压静电场(low voltage electrostatic field,LVEF)处理对蝴蝶兰切花保鲜效果的影响,该研究以蝴蝶兰切花品种“天堂鸟”为试验对象,探究了低压静电场处理对蝴蝶兰切花瓶插期间观赏品质、理化指标及相关酶活性的变化,并通过低场核磁共振(low-field nuclear magnetic resonance,LF-NMR)技术分析蝴蝶兰切花的水分迁移和水分流失情况。结果表明:瓶插第28天时,与对照组相比,低压静电场组的蝴蝶兰切花能保持较好的外观形态,其鲜质量和花径分别显著(P<0.05)提高4.88%、4.98%,可溶性糖含量和可溶性蛋白含量分别显著(P<0.05)提高了0.75、4.09 mg/g,相对电导率和丙二醛(malondialdehyde,MDA)含量分别显著(P<0.05)降低了31.53%、21.96 nmol/g,超氧化物歧化酶(superoxide dismutase,SOD)、过氧化物酶(peroxidase,POD)和过氧化氢酶(catalase,CAT)的活性峰值分别显著(P<0.05)提高了19.58、20.77、20.21 U/g,同时,结果表明低压静电场处理延缓了蝴蝶兰切花的水分迁移和水分流失现象。综上,低压静电场处理延缓了蝴蝶兰切花的品质劣变,该研究结果可为其他切花的保鲜应用提供一定的理论依据和技术参考。展开更多
本实验以鲜肉和传统冰箱冻结(-18℃,36 h)为对照,探究低频交变磁场辅助冻结(low-frequency alternating magnetic field assisted freezing,LF-MFF)、-18℃条件下处理不同时间(12、24、36 h和48 h)对猪肉品质的影响,分析不同条件冻结处...本实验以鲜肉和传统冰箱冻结(-18℃,36 h)为对照,探究低频交变磁场辅助冻结(low-frequency alternating magnetic field assisted freezing,LF-MFF)、-18℃条件下处理不同时间(12、24、36 h和48 h)对猪肉品质的影响,分析不同条件冻结处理后肉样冻结速率、保水性、嫩度、色泽、pH值等理化特性、水分迁移及流变特性的变化。结果表明:与传统冰箱冻结相比,在3 mT低频交变磁场处理条件下,肉样的冻结速率更快,猪肉的品质得到明显改善(P<0.05);所有冻结方式处理中,LF-MFF 36~48 h可提高样品的保水性、色泽和嫩度(P<0.05),维持了更好的理化品质;低场核磁共振(low field nuclear magnetic resonance,LF-NMR)结果显示,与冰箱冻结相比,LF-MFF 36~48 h后显著提高了样品不易流动水的比例,降低了自由水比例(P<0.05);动态流变结果也表明,LF-MFF 36~48 h后样品G’值较高,蛋白质变性程度较低,形成了较好的黏弹性蛋白凝胶。Pearson相关性分析表明,不同冻结处理后猪肉理化特性与水分迁移的变化具有较强的相关性。因此LF-MFF 36~48 h可作为最佳的猪肉冻结条件,可较好地维持猪肉理化特性,降低水分子的迁移率,延缓蛋白变性,改善冻结猪肉的品质。展开更多
低频电场解冻(low-frequency electric field thawing,LFEFT)与常温解冻(room temperature thawing,RTT)会导致牛肉pH值、颜色、总挥发性盐基氮(total volatile base nitrogen,TVB-N)含量、质构特性和持水力等方面显著不同,从分子水平解...低频电场解冻(low-frequency electric field thawing,LFEFT)与常温解冻(room temperature thawing,RTT)会导致牛肉pH值、颜色、总挥发性盐基氮(total volatile base nitrogen,TVB-N)含量、质构特性和持水力等方面显著不同,从分子水平解析LFEFT对牛肉品质影响的可能机制,采用蛋白质组学技术对2种解冻方式牛肉进行分析。结果表明:LFEFT组与RTT组之间有551个差异丰度蛋白(differentially abundant proteins,DAPs),其中14种DAPs与牛肉品质特性(pH值、色泽、TVB-N含量、质构和持水力)呈显著相关;生物信息学分析表明,DAPs主要参与蛋白结合、代谢酶和蛋白质周转等生物功能。LFEFT既可以提高生产效率,又保证了牛肉品质。展开更多
基金supported by a grant from National Defense Science and Technology Innovation Special Zone of China(02-ZT-008).
文摘Objective This work examines the impact of external electric fields at terahertz(THz)frequencies on doublestranded deoxyribonucleic acid(dsDNA)systems adsorbed on Au(111)surfaces in aqueous environments.Methods The investigation utilizes a molecular dynamics(MD)approach at the atomic level and vibrational dynamics calculations using the GolDNA-Amber force field.Results The results reveal that the sugar-phosphate backbone of the DNA exhibits reduced adherence to the gold surface,while the side chains display a stronger affinity.When subjecting the hydrated DNA strands to an electric field with frequencies up to 10 THz,peak intensities of vibrational dynamic density(VDoS)are observed at five different frequencies.Moreover,the strong electric field causes hydrogen bonds in the DNA within the slit to break.The sensitivity to the electric field is particularly pronounced at 8.8 THz and 9.6 THz,with different vibrational modes observed at varying electric field strengths.Conclusion These findings contribute to an enhanced understanding of the molecular organization of gold-plated charged biological interfaces.
文摘低频电场解冻(low-frequency electric field thawing,LFEFT)与常温解冻(room temperature thawing,RTT)会导致牛肉pH值、颜色、总挥发性盐基氮(total volatile base nitrogen,TVB-N)含量、质构特性和持水力等方面显著不同,从分子水平解析LFEFT对牛肉品质影响的可能机制,采用蛋白质组学技术对2种解冻方式牛肉进行分析。结果表明:LFEFT组与RTT组之间有551个差异丰度蛋白(differentially abundant proteins,DAPs),其中14种DAPs与牛肉品质特性(pH值、色泽、TVB-N含量、质构和持水力)呈显著相关;生物信息学分析表明,DAPs主要参与蛋白结合、代谢酶和蛋白质周转等生物功能。LFEFT既可以提高生产效率,又保证了牛肉品质。