3 edition of A study of lung surfactant (BLES) and dipalmitoyl phosphatidylcholine (DPPC) films using axisymmetric drop shape analysis (ADSA) found in the catalog.
Thesis (M.Sc.) -- University of Toronto, 1999.
|Statement||National Library of Canada|
|Publishers||National Library of Canada|
|The Physical Object|
|Pagination||xvi, 134 p. :|
|Number of Pages||74|
|2||Canadian theses = -- Thèses canadiennes|
nodata File Size: 9MB.
A detailed analysis of drop shapes and accuracy of measured surface tension values was performed using a shape parameter concept.
At higher surface pressures, the films became brittle and the elasticity decreased. DPPC, SP-C and mixtures of both. This means a more ideal mixing of the components in the monolayer. However, it was shown that DPPC monolayers can be compressed repeatedly up to the range of over-compression without totally collapsing, e.
The second maximum of dilatational viscosity in the range of film over-compression corresponds very well with the local maximum of elasticity in the same range. The captive bubble method in combination with the axisymmetric bubble shape analysis was shown to be suitable to characterise such systems. Work is also done on examining the interaction between tear film lipids and silicone hydrogel SiHy contact lenses.
Finally, it is noted that the ADSA--CSD setup developed here can be used for a wide range of colloid and surface chemical applications. The temperature dependence of D in CBF stabilised by DPPC, the major HFLS phospholipid component curve 5by HLFS alone curves 1 and 2 and by the reconstituted surfactant, comprised of SP-A added to HFLS curve 3 and 4 are shown in Fig.
DPPC was spread at the air bubble surface. Unlike the reproducible hysteresis noted for natural-lung-surfactant monolayers [ 382—384], the initial hysteresis observed with microbubble-surfactant monolayers during the first compression—expansion cycle does not recur in subsequent cycles; consequently, the material squeezed out of microbubble-surfactant monolayers during the initial compression phase evidently does not reenter the monolayer upon subsequent expansion.
3 made it apparent that the glycopeptide:acyl lipid weight ratio in the stable, microbubble-surfactant monolayer was quite low cf. 9 shows the dilatational viscosity corresponding to the elasticity data of Fig. After some oscillations however the level of y decreases and the oscillation becomes more and more sinusoidal. the minimum area demand of the DPPC molecule.the hydrolysis rate of polyesters and drug release [ 68]. the range where the minimal area demand per molecule falls below the molecular cross section .
Surface dilatational rheological behaviour was characterised by sinusoidal oscillation of the bubble volume and at frequencies 0. There are, however, only few methods to determine such parameters. These results are valuable also in relation to the application of foam bilayers for assessment of lung maturity in clinical practice.
With the introduction of CsA in the 1980s, lung transplantation became a more feasible treatment option, and the control of the immune system kept advancing.
For example, it has been demonstrated [ 36] that there exists an upper limit of the gel phase content in membranes above which the membrane morphology and permeability change dramatically thus making the execution of the physiological functions of the membrane impossible.
There is a lot of controversy surrounding the role of the surfactant, and the veracity of the various tissue models.