Deep levels,transport and THz emission properties of SiGe/Si quantum-well structures

In coal mines in such countries as China and Russia,most of the coal mine methane(CMM) generated during mining is emitted to the atmosphere without any effective usage,because the methane concentration of CMM is relatively low and not allowed to be used as fuel for safety reasons.Methane is one of the greenhouse gases.Therefore,if it becomes possible to concentrate CMM to an acceptable level for use as fuel,this will greatly contribute to reduction of greenhouse gas emissions.With the aim of gaining approva...     

抗氧化剂抑制内皮细胞表面的白细胞粘附不依赖其抗氧化活性

氧张力是炎症反应、再灌注损伤和动脉粥样硬化形成的致病因素。这些病变的共同点是内皮细胞表面的白细胞粘附增加。我们用几种抗氧化剂：ＤＣＩ,Ｃｈｒｙｓｉｎ,ＰＤＴＣ和Ｐｒｏｂｕｃｏｌ在流动条件下（切变力在０６～２４ｄｙｎ／ｃｍ２）实验其对内皮细胞表面白细胞粘附的影响,用化学发光法分析这几种抗氧化剂的抗氧化活性。结果显示：ＰＤＴＣ和Ｐｒｏｂｕｃｏｌ对外周血有核细胞氧自由基的产生没有抑制作用,Ｃｈｒｙｓｉｎ可轻度抑制,ＤＣＩ可明显抑制活性氧的产生。相反,ＰＤＴＣ（最大半抑制量８×１０－４ｍｏｌ和Ｃｈｒｙｓｉｎ最大半抑制量５×１０－５ｍｏｌ）可抑制细胞对经ＴＮＦα刺激的人脐带静脉内皮细胞（ＨＵＶＥＣ）的粘附。ＤＣＩ和Ｐｒｏｂｕｃｏｌ对各种切变力范围的细胞粘附无作用。抗氧化剂对内皮细胞表面的白细胞粘附的抑制作用不能单用其抗氧性特性来解释。可能的作用机理是这类物质直接作用转录因子ＮＦ－ｋＢ的结果