豆奶甲醇提取物中抗氧化活性物质的鉴定

本文主要在研究了豆奶甲醇提取物有无抗氧化活性的基础上,分析鉴定了其可能存在的抗氧化物质,为相关研究提供理论依据。测定抗氧化能力的方法包括1,1-二苯基-2-三硝基苯肼(1,1-Diphenyl-2-picrylhydrazyl radical, DPPH)法和铁离子还原能力(Ferric reducing antioxidant power ,FRAP)法。比色法测定总酚含量和总黄酮含量。通过超高效液相-四极杆飞行时间串联质谱(Ultra-high performance liquid chromatography-quadruple time-of-flight-mass spectrometry, UHPLC- QTOF-MS)测定豆奶甲醇提取液中活性成分的种类和含量。实验表明,豆奶甲醇提取液具有一定的抗氧化性,且DPPH法和FRAP 法测定豆奶抗氧化值不存在显著性差异。豆奶甲醇提取物的总酚含量(285.77±2.93 μg/mL)远高于总黄酮含量(11.27±0.51 μg/mL)。鉴定出5种化合物,其中只有6,7,4'-三羟基黄酮和Rha-Ara-GlcA-SoyB与抗氧化值存在正相关性。异黄素和大豆甙元两种异黄酮与抗氧化值存在着负相关,6,7,4'-三羟基黄酮可能是主要的抗氧化物质。     

Advanced fault collapsing [logic circuits testing]

The partitioning of faults into equivalence classes so that only one representative fault per class must be explicitly considered in fault simulation and test generation, called fault collapsing, is addressed. Two types of equivalence, which are relevant to the work reported, are summarized. New theorems on fault equivalence and dominance, forming the basis of an algorithm that collapses all the structurally equivalent faults in a circuit, plus many of the functionally equivalent faults, are presented. Application of the algorithm to a set of benchmark circuits establishes that identification of functionally equivalent faults is feasible, and that, in some cases, they are a large fraction of the faults in a circuit. The collapsing algorithm applies not only to combinational designs but to synchronous sequential circuits as well