BACKGROUND Preoxygenation with tidal volume breathing for 3 min is commonly used technique. An end tidal expiratory oxygen concentration greater than 90% is considerd to be adequate for preoxygenation. The aim of this study was to check the effects of preoxygenation on elderly patients through the comparison with young patients during the 3 min tidal volume breathing technique. METHODS Sixty ...

In the biosynthesis of haem pigments, the concentration of oxygen appears to play a regulatory role at the sites of specific reactions in the pathway. The release of iron from storage in liver ferritin (Green & Mazur, 1956) and the catalysis, by soluble liver ferrochelatase preparations, of the incorporation of Fe2+ ions into protoporphyrin to form haem (Porra & Jones, 1963) are both favoured b...

Despite oxygen is believed to be the most important environmental factor for any aerobic microbial process, the quantitative studies of its influence on growth and metabolite formation on the level of individual pellets formed by filamentous fungi were seldom performed. Never was it made for lovastatin producer Aspergillus terreus ATCC20542. Thus, this work is a quantitative study of oxygen tra...

A complete pH and blood gas analysis of arterial and mixed venous blood may comprise more than forty different quantities. We have selected sixteen, including patient temperature. The arterial oxygen tension group includes the oxygen tension, fraction of oxygen in inspired air, and fraction of mixed venous blood in the arterial (total physiological veno-arterial shunting). The haemoglobin oxyge...

We developed a novel single cell measurement of photosynthesis activity using fluorescent oxygen sensor in a microchamber with gas barrier layer. We used Synechocystis sp. PCC 6803, which is a series of cyanobacteria. The chamber wall contains oxygen sensor and gas barrier layer to measure the dissolved oxygen concentration in the chamber. The oxygen concentration is changed by aerobic respirat...

Experiments were conducted to study CCA-treated wood combustion over a range of temperature and oxygen concentrations with a view to understanding the factors affecting energy and metals recovery from waste treated timber. CCA-treated wood was burned in a furnace at temperatures from 400 to 940 degrees C and oxygen concentrations between 5 and 21%. The ash and condensed volatiles were digested ...

Variations in blood oxygen concentrations are not only part of the normal physiology but they may also indicate various pathological conditions. In the present work, we examined the influence of oxygen concentration on the rheological properties of whole human blood. Blood samples were taken from two healthy donors, a male and a female, with hematocrits 0.47 and 0.42, respectively. In addition ...

Despite the fact that there are wastewater treatment plants (WWTPs) currently operational across Iran and great advances have been made in this area, there are still problems in the design, construction, and operation of WWTPs with large nonlinear systems, varying flow rates, and pollution charges. The objective of this study was to investigate the effect of operating parameters including the r...

Glucose concentration may be determined enzymatically by a glucose-oxidase procedure in which the amount of oxygen depletion from a solution saturated with oxygen is observed. The difference between the initial and final oxygen levels as detected by a polarographic oxygen analyzer is a measure of glucose concentration. Blood is sampled continuously by means of a double-lumen catheter inserted i...