维生素与防治高血压相关性的研究进展

高血压是一种常见的慢性病,其成因是多方面的,既受遗传因素影响,也会因为不良的生活习惯而形成。高血压易引发患者心脑血管疾病,长期持续的高血压最终会导致心脑血管衰竭,甚至危及生命安全。为控制高血压发生和恶化,不同国别的研究人员都做了大量的实验,并得到了可靠的数据。有研究数据表明补充维生素可能对高血压防治具有一定的作用。为了进一步探索补充维生素与防治高血压的相关性,本文以近些年来的相关研究为依据,概述了高血压的成因和危害,综合论述了维生素C、维生素D和维生素E这三种维生素与防治高血压的相关性及可能的作用机理。希望能帮助高血压患者在日常饮食或营养素补充过程中,通过控制维生素的摄入来降低高血压恶化的风险。     

Characteristic emission of negatively charged particles during tensile deformation of oxide-covered aluminum alloys

Electrons, positive and negative ions as well as photons are known to be emitted from oxide- covered pure polycrystalline Al, Ni, and Ti during tensile deformation. It has been shown that the propagation of cracks in the oxide is uniquely associated with this so-called tribo-stimulated exoemission phenomenon. In this paper we report recent results of tribo-stimulated emission of negatively charged particles from bare and Al-clad aluminum alloys. The investigated samples were anodically oxidized under various conditions such as to produce oxide layers of different thickness as well as chemical and mechanical properties. Of particular interest in this connection are certain porous oxides which facilitate adhesive bonding. The characteristic exoemission curve (emission rate versus strain of the Al substrate) is obtained by measuring the number of emitted negative particles as a function of strain ϵ during tensile deformation of the sample with a constant strain rate dϵ/dt. The features of the curves obtained from different oxides are compared. Initial evidence is presented indicating that the exoemission curve is unique for a given oxide- metal alloy system and has potential as a monitor of certain characteristics of the oxide layer.