Because oxygen is vital to the metabolic processes of all eukaryotic cells, a detailed understanding of its transport and consumption is of great interest to researchers. Existing methods of quantifying oxygen delivery and consumption are non-ideal for in vivo measurements. They either lack the three-dimensional spatial resolution needed, are invasive and disturb the local physiology, or they rely on hemoglobin spectroscopy, which is not a direct measure of the oxygen available to cells. Consequently, many fundamental physiology research questions remain unanswered. This dissertation presents our development of a novel in vivo oxygen measurement technique that seeks to address the shortcomings of existing methods. Specifically, we have combined two-photon microscopy with phosphorescence quenching oximetry to produce a system that is capable of performing depth-resolved, high-resolution dissolved oxygen concentration (PO2) measurements. Furthermore, the new technique allows for simultaneous visualization of the micro-vasculature and measurement of blood velocity. We demonstrate the technique by quantifying PO2 in rodent cortical vasculature under normal and pathophysiologic conditions. We also demonstrate the technique’s usefulness in examining the changes in oxygen transport that result from acute focal ischemia in rodent animal models. / text

An arterialblood gas analysis which is conducted in critical care areas contributes to the assessment of a patient's ventilatory status and acid -base balance. The purpose of this research was to determine the relationship of time delays and temperature on the result of a blood gas analysis. The objective was to either accept or refute the null hypothesis, that there is no relationship between temperature and time delays and an arterial blood gas result Fifteen subjects were randomly selected. The researcher drew three samples of arterial blood from each subject. Ethical principles were observed. An inferential non-parametric statistic was used. The chi-squared test was used to test the hypothesis and the Friedman and the Wilcoxon signed ranks test were used to test the differences between the means. The results revealed that there was a relationship between time delays, temperature and the arterial blood gas result. The null hypothesis was rejected. / Health Stusies / M.A. (Health Studies)

An arterialblood gas analysis which is conducted in critical care areas contributes to the assessment of a patient's ventilatory status and acid -base balance. The purpose of this research was to determine the relationship of time delays and temperature on the result of a blood gas analysis. The objective was to either accept or refute the null hypothesis, that there is no relationship between temperature and time delays and an arterial blood gas result Fifteen subjects were randomly selected. The researcher drew three samples of arterial blood from each subject. Ethical principles were observed. An inferential non-parametric statistic was used. The chi-squared test was used to test the hypothesis and the Friedman and the Wilcoxon signed ranks test were used to test the differences between the means. The results revealed that there was a relationship between time delays, temperature and the arterial blood gas result. The null hypothesis was rejected. / Health Stusies / M.A. (Health Studies)