Figure 5.(a) Responses to 10 ppm H2S of Cu-SnO2, WO3 and In2O3 as a function of operating temperature and (b) Reproducibility of the film response neither to 10 ppm H2S at their optimum operating temperature.Comparing to the literature, the Cu-SnO2 prepared in this work presents higher response at lower operating temperature than some other Cu-SnO2 materials fabricated Inhibitors,Modulators,Libraries with different techniques [8]. In the same way, the performances of WO3 are superior to those reported in [29]. On the contrary, the response obtained in [10] is higher than that of our films, but with the disadvantage of a recovery process possible only by applying heating pulses at 250 ��C.
Concerning the In2O3 films in the detection of H2S, there are just few dedicated papers in the literature [30-32], and
Low-molecular-weight Inhibitors,Modulators,Libraries antioxidants (LMWAs) are a wide group of quite small molecules providing electrons to oxidizing agents which protect other molecules from oxidation in this way. LMWAs are oxidized during this process. The localization of various LMWAs is different. Glutathione is predominantly found in plasma, ascorbate in whole blood and alpha-tocopherol protects membranes [1]. Apart from LMWAs of non-enzymatic nature, the endogenous antioxidant defences also include enzymatic antioxidants critical for the control of reactive-molecular-species-mediated oxidative damage of biomolecules. However, the effect of enzymatic antioxidants is completely different to that of LMWAs. They cleave reactive oxygen species.
Enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione reductase (GR) may be mentioned as typical Inhibitors,Modulators,Libraries examples of enzymatic antioxidants [2,3]. It is common for the enzymatic antioxidants be assayed using standard biochemical procedures [4]. On the other hand, LMWAs are assayed using different analytical methods for functional groups in the antioxidant molecule and/or its redox power.Some LMWA assays are based on the enzymatic cleavage of antioxidants. This approach was used, for example, by Vermeir et al. [5], who fabricated a calorimetric biosensor Inhibitors,Modulators,Libraries with trapped ascorbate oxidase and the biosensor was successfully used for the assay of the ascorbate in complex matrices such as food and drugs. Thiol-group containing antioxidants may be simply assayed by reaction with Ellman’s reagent (5,5��-dithio-bis(2-nitrobenzoic acid)) which affords yellow coloured 5-thio-2-nitro-benzoic acid with an absorption at 412 nm [6,7].
Oxidized AV-951 glutathione (GSSG) may be converted into the reduced form glutathione (GSH) using the enzyme GR and in this way it is possible to assay both forms [8].The Ruxolitinib supplier typical methods suitable for assay of the antioxidant potency are based on the reaction between antioxidants and chromogens which result in some colour change due to the redox reaction. Antioxidants may be assayed by the oxygen radical absorbance capacity (ORAC) based on fluorescein or beta-phycoerythrin.