Oxygen consumption, measurement comparative measurements

In older rats (12-14 weeks), there was a significant increase in relative lung weights as compared to controls following 6 weeks of exposure to 260 ppm hexachloroethane. Oxygen consumption was not measured in these animals, and it is not clear if the tissues were examined histologically (Weeks et al. 1979). 

In further metabolic studies [119], heat production and oxygen consumption rates were measured in plasma from uremic patients on chronic haemodialysis treatment. Both were found to be significantly increased compared to healthy subjects, and also when compared to patients on continuous ambulatory peritoneal dialysis (see Table 29). 

The material balance is consistent with the results obtained by OSA (S2+S4 in g/100 g). For oil A, the coke zone is very narrow and the coke content is very low (Table III). On the contrary, for all the other oils, the coke content reaches higher values such as 4.3 g/ 100 g (oil B), 2.3 g/ioo g (oil C), 2.5 g/ioo g (oil D), 2.4/100 g (oil E). These organic residues have been studied by infrared spectroscopy and elemental analysis to compare their compositions. The areas of the bands characteristic of C-H bands (3000-2720 cm-1), C=C bands (1820-1500 cm j have been measured. Examples of results are given in Fig. 4 and 5 for oils A and B. An increase of the temperature in the porous medium induces a decrease in the atomic H/C ratio, which is always lower than 1.1, whatever the oil (Table III). Similar values have been obtained in pyrolysis studies (4) Simultaneously to the H/C ratio decrease, the bands characteristics of CH and CH- groups progressively disappear. The absorbance of the aromatic C-n bands also decreases. This reflects the transformation by pyrolysis of the heavy residue into an aromatic product which becomes more and more condensed. Depending on the oxygen consumption at the combustion front, the atomic 0/C ratio may be comprised between 0.1 and 0.3 ... 

Figure 4.15 indicates the range of rates of O2 consumption in different soils. Oxygen is consumed in oxidation of inorganic reductants, such as Fe(II), as well as in oxidation of organic matter by microbes. Bouldin (1968) and Howeler and Bouldin (1971) compared measured rates of O2 movement into anaerobic soil cores with the predictions of various models, and obtained the best fits with a model allowing for both microbial respiration and abiotic oxidation of mobile and immobile reductants abiotic oxidation accounted for about half the O2 consumed. The kinetics of the abiotic reactions are complicated. They often depend on the adsorption of the reductant on solid surfaces as, for example, in... 

A decreased activity of the stimulated oxygen consumption 3 hours after cell isolation has been shown (M5). When superoxide production is measured on the same preparation of leukocytes, the decrease observed over the same period of time is comparable to that found when measuring oxygen consumption (Fig. 5). Takeshige et al. (Tl) reported a 30% loss of activity 6 hours after blood sampling when they measured Oi production and a 50% loss of activity after 5 hours when they determined H2O2 production. 

Comparative Measurements of Oxygen Consumption with Spectrophotometrically Calibrated Substrates... 

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