Antioxidative factor, definition

Reactive oxygen species (ROS), oxidative stress and the environment form a complex relationship with important influence on human health and disease. Environmental oxidative stress derives from different artificial and natural sources (Fig. 1) and is induced by several different mechanisms. To address the complexity of this field, this chapter will deal with the modes of action by which environmental factors can disturb the equilibrium between pro- and antioxidants favouring the former (for definition of oxidative stress see [1]). Adjacent, environmental sources of oxidative stress and their mode of action will be introduced. 

In conclusion, although it is yet to be definitively shown, much evidence supports a link between oxidation of lipoproteins and arteriosclerosis in human beings. If this relationship can be conclusively demonstrated, it is likely there will be a need to measure lipoprotein oxidation products in the clinical laboratory for risk assessment. Establishing a definitive link between oxidation and arteriosclerosis is not a simple task because not only will it be necessary to demonstrate that oxidation is a risk factor for arteriosclerosis in large prospective studies, but it will be important to show it is a marker independent of lipoprotein and inflammatory markers. Furthermore, it would be desirable to identify treatments by which modification of oxidation markers leads to reduction in disease (SI). To date, the failure of randomized trials with antioxidant nutrients to retard arteriosclerosis (Al, Y3) has made it clear that demonstrating a definite relationship in humans may be more difficult that expected. In the meantime, there is a need to measure these... 

The material life time can be calculated by means various experimental procedures, which provide relevant information obtained by stmctural modifications. The long-term stability is estimated for the preservation of upper-limit performances and longest operation periods over several degradation cycles with high irradiation fluxes. In fact, the durability is expressed by the reliability of material behavior, which is described by the failure rate. The definition of durability must also include the condition of testing irradiance, duration, complementary environmental factors, physical properties (crystallinity, hardness, viscosity, diffusion constant), homogeneity, presence of antioxidant, especially for engineering polymers [24]. 

---