To mimic the properties of haemoglobin (Hb) and myoglobin (Mb) it has been found necessary to synthesise a five-coordinate ferrous porphyrin with a protecting structure over the sixth coordination site at iron. This thesis describes approaches to the synthesis of such a compound where the protecting structure is the "capped" moiety and where the base which occupies the fifth coordination site is held in position by two covalent linkages to the porphyrin. The preparation of the target molecule involved the synthesis of a new "capped" porphyrin and a series of difuncticnalised pyridines. These were then successfully coupled under high dilution conditions to give the "capped/strapped" porphyrin. Metallation and reduction completed the synthesis. The behaviour of the ferrous complex in the presence of dioxygen was investigated. High stability toward irreversible oxidation was found. In the presence of oxygen the ferrous complex had a half-life in excess of 40h at room temperature.

Bibliography: p. 171-181. / xxiii, 181 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / The comparision of the pond and field plants suggests both species are eminently more suited to static water regime where adaptations by the plant can be made effectively to help with the problem of oxygen transport. The results also suggest that plants experience a variable and static water regime differently. / Thesis (Ph.D.), University of Adelaide, Dept. of Botany, 1999

No description available.

An experimental investigation was done on oxygen transfer into a steady, laminar flow of whole blood and hemoglobin solutions. The effects of facilitation and augmentation on the bulk transfer were studied. The transfer problem was modeled numerically and effective diffusivities were calculated for all of the experiments. Significant increases in transfer due to both facilitation and augmentation were observed. Ghost cells were found to have no effect on transfer into hemoglobin solutions. / Master of Science

In situ biodegradation of p-xylene was studied in a 2.75 inch diameter column using oxygen microbubbles to supply the electron acceptor. One objective was to demonstrate that pxylene can be biodegraded in the soil column and to follow the degradation and pressure drops as a function of time. The next objective was to demonstrate the potential for biodegradation of p-xylene in the presence of ferrous iron and to follow bioremediation and anticipated pressure drops as a function of time. Then, an air sparging section was added prior to the biodegradation section to determine if the ferrous iron could be removed in this section. The air sparging section would then be flushed with air and/or water to determine if the ferrous could be removed from the sand matrix and alleviate the expected plugging. The bacteria degraded p-xylene to below detectable limits until the oxygen supply was exhausted. The pressure drops over this time showed a slight increase over the first few days and then a gradual decline, which shows promise for in situ biodegradation as the microorganisms were thought to cause plugging. The next run which studied the simultaneous biodegradation of xylene and ferrous oxidation showed no interference from the ferrous iron. The microorganisms seemed to store the oxygen that they needed before the ferrous could oxidize. The pressure drops showed no general trend, therefore the ferric precipitate did not cause an appreciable amount of plugging as expected. The air sparging section resulted in volatilization of xylene with very little ferrous oxidation. To flush the ferric precipitate from this zone, either a combination of air sparging and backwashing or backwashing at the fluidization velocity was needed to remove the ferric iron. / Master of Science

Oxygen transfer was studied within the arterioles and venules (40 to 100 μm in diameter) of a hamster cheek pouch retractor muscle. Previously obtained transluminal oxygen saturation, red blood cell velocity, and hemoglobin concentration were used for the analysis. Because of branching and transfer to the tissue, the measured oxygen profiles across the vessels were nonuniform. At each axial location, the profiles were converted to radial distributions using a convolution algorithm. The results were modeled using a numerical solution of the convective mass transport equation assuming the blood to be a homogenous mixture. Effective diffusion coefficients were found by matching the axial development of the radial oxygen distribution predicted by the analytical model with the experimental data. The resulting oxygen diffusion coefficients were an order of magnitude higher than have been measured in vitro. This appears to support other evidence relating to the higher than expected oxygen transport in the microcirculation. / Master of Science

An experimental investigation was done on oxygen transfer into a laminar flow of whole blood and saline solutions downstream of an abrupt pipe expansion. This was used as the experimental model for regions of separated flow in the arterial system. The flow was fully-developed prior to the expansion with Reynolds numbers between 160 to 850. The results showed high transfer rates over most of the region downstream of the step, with maximum transfer occurring near the reattachment point. In addition, oscillations of the transfer rate were measured at the larger Reynolds numbers of 450 and 850. / Master of Science

Thesis (M Sport Sc)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: Compression socks (CS) are used as an ergogenic aid during and after exercise by many athletes of elite and recreational status. The exact mechanism whereby CS affect performance and postexercise recovery is not yet elucidated. Some research ascribes the beneficial effects to improved lactate removal rates with CS. One hypothesis is that CS improve venous return and thereby remove the lactate from the tissue to other tissues such as the liver, and the second hypothesis is that the CS cause retention of the lactate within the muscle and therefore improve the oxidation of the lactate within the muscle (Berry & McMurray, 1987). The current study endeavoured to test the hypothesis set by Berry and McMurray (1987) by measuring the effect of CS as well as flight socks (FS) on muscle oxygenation during exercise and recovery in endurance trained runners and triathletes. Eleven male endurance trained runners and triathletes (age = 34.8 ± 3.8 years, VO2max = 52.4 ± 7.1 mL.kg-1.min-1) participated in the study. They completed an incremental exercise test to exhaustion to determine their maximal aerobic capacity (VO2max) and peak treadmill velocity (PTV). Then they completed two 10 km treadmill running tests at 80 % of their PTV. During these two trials participants wore either CS or FS; the order of treatment was randomly selected. A subset of the study sample (n = 5) also completed a control test wearing only their ankle length sport socks (NS). After these trials, participants completed a 60 minute passive recovery period in the seated position while muscle oxygenation was measured. Compression under the socks was measured at several anatomically determined measurement points prior to the commencement of the exercise test, along with the determination of blood haemoglobin concentration ([Hb]). During the exercise trials, blood lactate concentration ([BLa]), skin temperature (ST),oxygen consumption (VO2), carbon dioxide production (VCO2), heart rate (HR), and muscle oxygenation variables (oxy-haemoglobin (O2Hb), deoxy-haemoglobin (HHb), tissue oxygenation index (TOI) and total haemoglobin index (nTHI)) was measured . During the 60minute passive recovery period, [BLa], ST, O2Hb, HHb, TOI, and nTHI measurements were continued. The results showed that there were differences in the pressure exerted between the two pressure condition (CS and FS) at the posterior ankle, and under the elastic of the sock as well as on the anterior calf at the level of greatest calf circumference. Differences in ST between the CS and NS and the FS and NS conditions were found between the first four 2 km intervals of the exercise protocol, but not during recovery. No differences were found in [BLa] between the three different compression conditions during either the exercise (p = 0.19) or recovery period (p = 0.63), as well as no differences in the cardiorespiratory variables during exercise between the three different compression conditions (VO2, p = 0.06; VCO2, p = 0.12; HR, p = 0.36). With regard to the muscle oxygenation variables, no differences were found between the three compression conditions during exercise, however there was a trend for lower oxygen utilization (HHb) during exercise in the NS condition (p = 0.57, medium to large practical significance). There were also no differences in these variables (O2Hb, p = 0.65; HHb, p = 0.57; TOI, p = 0.39; nTHI, p = 0.22) during recovery, although oxygen utilization (HHb) showed a faster recovery rate with increasing external pressure. From the results obtained, it seems that external compression caused a decrease in the blood flow velocity within the muscle, thereby increasing oxygen diffusion rate. During exercise this did not facilitate differences in [BLa], however, after the first 10 minutes of the recovery period, large practical differences were found between the NS and both sock conditions, suggesting that the increase in oxygen diffusion improved lactate clearance. This could support the hypothesis set by Berry and McMurray (1987). / AFRIKAANSE OPSOMMING: Kompressie sokkies (CS) word gereeld deur beide rekreasie- en elite atlete gebruik as ‘n ergogeniese hulpmiddlel tydens oefening en herstel. Die presiese meganisme waardeur CS prestasie en post-oefening herstel beïnvloed is nog nie volledig verklaar nie. Sommige navorsing skryf die voordelige effekte toe aan die vinniger herstel van laktaat in die sirkulasie. Daar is tans twee hipoteses vir die meganisme waardeur CS laktaat verwydering verbeter. Die eerste hipotese is dat CS die veneuse terugvoer verbeter en daardeur die laktaat van die weefsel verwyder en na ander weefsels soos die lewer vervoer vir verwydering. Die tweede hipotese is dat CS veroorsaak dat die laktaat in die spierweefsel teruggehou word wat dan tot gevolg het dat die laktaat in die spier self deur middel van oksidasie verwyder word (Berry & McMurray, 1987). Hierdie studie poog om Berry en McMurray (1987) se hipotese te toets deur die effek wat CS sowel as vlugsokkies (FS) op spieroksigenasie het gedurende oefening en herstel in geoefende uithouvermoë hardlopers en driekamp atlete vas te stel. Elf ingeoefende langafstand hardlopers en driekampatlete (mans) (ouderdom = 34.8 ± 3.8 jaar; VO2maks = 52.4 ± 7.1 mL.kg-1.min-1) het aan hierdie studie deel geneem. Die deelnemers het ‘n inkrementele toets tot die punt van uitputting voltooi om hul maksimale aërobiese kapasiteit (VO2maks) en piek trapmeul snelheid (PTV) vas te stel. Die elf deelnemers het ook twee 10 km hardlooptoetse teen 80 % van hul PTV voltooi. Gedurende hierdie twee toetse het die deelnemers óf CS óf FS gedra; die volgorde van die intervensie was lukraak aan hulle toegeken. ‘n Subgroep van die steekproef (n = 5) het ook ‘n kontrole toets voltooi waartydens hulle hul eie enkelhoogte sport sokkies (NS) gedra het. Aan die einde van die hardloop protokol het die deelnemers ‘n 60 minuut passiewe herstel periode in die sittende posisie voltooi terwyl spieroksigenasie gemeet is. Kompressie onder die sokkies is voor die aanvang van die hardloop protokol by verskeie anatomies gedefinieerde punte gemeet. Verder was die bloed hemoglobien konsentrasie ([Hb]) ook gemeet voor die hardloop protokol. Tydens die oefeningtoets is bloedlaktaat konsentrasie ([Hb]), veltemperatuur (ST), suurstof verbruik (VO2), koolstofdioksied produksie (VCO2), harttempo (HR), sowel as spieroksigenasie veranderlikes (oksi-hemoglobien (O2Hb), deoksi-hemoglobien (HHb), weefsel oksigenasie indeks (TOI), en totale hemoglobien indeks (nTHI)) gemeet. Gedurende die 60 minuut passiewe hersteltydperk is [BLa], ST, O2Hb, HHb, TOI en nTHI metings geneem. Die resultate toon dat daar ‘n verskil is in die druk wat uitgeoefen word in die onderskeie druktoestande (CS en FS) op die been by die posterior enkel en onder die rek van die sokkie, sowel as op die anterior kuit waar die kuit die grootste omtrek het. Verdere verskille tussen die CS en NS en die FS en NS toestande is in ST gevind in the eerste vier 2 km intervalle van die oefeningtoets, alhoewel geen verskille tydens die herstelperiode gevind is nie. Tydens beide die oefening (p = 0.19) en herstel (p = 0.63) protokol is geen verskille tussen die drie kompressie toestande met betrekking tot [BLa] gevind nie. En so ook is daar geen verskille tussen die onderskeie kompressie toestande in kardiorespiratoriese veranderlikes (VO2, p = 0.06; VCO2, p = 0.12; HR, p = 0.36) tydens oefening gevind nie. Met betrekking tot spieroksigenasie veranderlikes was daar geen verskil gevind tussen die drie kompressietoestande gedurende oefening nie, alhoewel daar ‘n tendens was vir die NS toestand om tydens oefening minder suurstofverbruik (HHb) (p = 0.57, medium tot groot praktiese effek) te lewer. So ook gedurende herstel is daar geen verskil in hierdie veranderlikes (O2Hb, p = 0.65; HHb, p = 0.57; TOI, p = 0.39; nTHI, p = 0.22) gevind nie, alhoewel die suurstofverbruik (HHb) vinniger na die basislyn herstel het met ‘n toename in druk. Die resultate toon dat eksterne kompressie ‘n afname in die bloedvloei tempo in die spier veroorsaak wat dan ‘n verlengde suurstof diffusie tyd veroorsaak. Hierdie verlengde suurstof diffusie tyd het geen effek op [BLa] tydens oefening gehad nie, alhoewel daar na die eerste 10 minute van die herstelperiode ‘n groot praktiese verskil tussen die NS en sokkie toestande gevind was in [BLa]. Hierdie verskil kan daarop dui dat die toename in suurstof diffusie verbeterde laktaat verwydering tot gevolg het, wat dan die hipotese van Berry en McMurray (1987) ondersteun.

The purpose of this study was to assess the changes in maximal oxygen consumption and cardiorespiratory responses to maximal treadmill exercise of men, who engaged in intense physical training for more than 35-years. Thirteen men were first studied in 1969 and were re-examined in 1992 as a 25-year follow-up. The men were divided into two groups, group 1 (G1) and group 2 (G2). G1 (current age = 54.6 years) consisted of seven men who were Division I cross country runners in the late 1960's, and G2 (current age = 67.5 years) were highly active at the initial testing and were 14 years older than the men of G1 at all test dates. A maximal exercise test revealed a significant decrease in absolute and realtiveVO2ma, over the 35-years for both G1 and G2. G2 experienced a significant decline in VO2max when expressed in relative and absolute terms after the age of 56.5 years which occurred after the 25-year test. Maximal heat rate decreased over the 35-year period for both G1 (187.7 to 165.8 bpm) and G2 (181 to 164.7bpm), however only GI revealed a trend between the 25-and 35-year tests. O2pulse significantly decreased from the initial testing to the 35-year period in G2 (23.1 to 19.5 ml/beat). Body composition changes were evident with aging in that both GI and G2 had a significant increase in percent body fat over the 35-years however, only Gl had a significant increase in body weight at both the 25-and 35-year follow-up.These data suggest that aging and a reduced training regimen may have a significant effect upon VO2m and cardiorespiratory and body composition measures. It appears that after the age of 56 years, a greater reduction in VO2max occurs, which is accompanied by greater changes in stroke volume. Although the aerobic capacity of these men declined over the 35-year period, the values obtained by all men far exceeded the values reported for sedentary and less active men in other studies. Therefore, as previously reported, aging is associated with a reduction in aerobic capacity, however continued endurance training can reduce the rate at which aerobic capacity declines. / Fisher Institute for Wellness and Gerontology

The hematological and rheological characteristics of blood from a number of vertebrates was compared to assess possible species differences in blood viscosity that may influence cardiovascular oxygen transport. Nucleated red blood cells (RBCs) were more viscous (measured by cone-plate viscometry) in comparison with enucleate (mammalian) RBCs at hematocrits greater than 40% when measured at equivalent temperatures. The lower viscosity of enucleate RBCs is attributed to an enhanced deformability of enucleate cells in comparison to nucleated cells.