Thesis (Ph. D.)--University of Missouri-Columbia, 2002. / Typescript. Vita. Includes bibliographical references (leaves 212-236). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 2002. / Typescript. Vita. Includes bibliographical references (leaves 212-236). Also available on the Internet.

Thesis (Ph. D.)--University of Texas at Austin, 2005. / Supervisor: Lynn Rew. Vita. Includes bibliographical references.

Thesis (Ph. D.)--University of Hong Kong, 2005. / Title proper from title frame. Also available in printed format.

Made available in DSpace on 2014-06-11T19:23:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2004Bitstream added on 2014-06-13T18:19:54Z : No. of bitstreams: 1 brinholi_rb_me_botfmvz.pdf: 2584808 bytes, checksum: 9d6b793f686390f6b23ad45cf38aaf38 (MD5) / Universidade Estadual Paulista (UNESP) / Os valores da densidade mineral óssea (DMO) da extremidade distal do rádio-ulna de 95 cães de diferentes portes e idades foram determinados por meio da técnica de densitometria óptica em imagens radiográficas. Para a medida da DMO foi utilizado um programa computacional que analisou a densidade óptica das radiografias confeccionadas em projeção crânio-caudal da extremidade distal do rádio-ulna e de partes moles adjacentes, juntamente com uma escala de alumínio (penetrômetro), usada como referência densitométrica, permitindo a medida da DMO do rádio-ulna, que corresponde ao valor em milímetros de alumínio da escala. Os valores da média e os desvios padrões da densidade mineral óssea da extremidade distal do rádio-ulna da amostra foram: 2,38 ± 0,70 mmAl para cães entre 01 e 10 Kg, 3,55 ± 1,04 mmAl para cães entre 10,1 e 25 Kg, e 4,69 ± 0,90 mmAl para cães com mais de 25 Kg. Ocorreu forte correlação (p<0,001) entre a DMO e o peso dos animais estudados, sendo que a DMO não foi significativamente influenciada pelo sexo e nem pela idade dos animais. / The values of bone mineral density (BMD) of distal ext remity radius - ulna of 95 dogs of different weights and ages were determinated using the technique of optical densitometry in radiographic images. To measure BMD it was used a computer software that analyses the optical density of radiographic in craniocaudal view from the distal extremity radius - ulna and adjacent soft parts, with an aluminum scale (penetrometer), used as a densitometry reference, allowing the measurement of the radius - ulna BMD, that corresponds to the value in millimeters of the scale. The mean values and the standard deviation of bone mineral density of the extremity radius - ulna of the sample were: 2,38 ± 0,70 mmAl for dogs between 01 and 10Kg, 3,55 ± 1,04 mmAl for dogs between 10,1 and 25Kg, and 4,09 ± 0,90 mmAl for dogs over 25Kg. There was a strong correlation (p<0,001) between the BMD and the studied animals weight, although BMD was not significantly influenced by the animals sex or age.

A retrospective case study of 3 patients that developed epithelial ingrowth after laser in situ keratomileusis (LASIK). This study was conducted at Boston Eye Group in Brookline, Massachusetts. The Oculus Pentacam was used to study corneal densitometry for each patient. Corneal densitometry readings were obtained for each patient pre-operatively and post-operatively after ingrowth was discovered. Densitometry was recorded at the central nest of opacity and at the leading edges of the ingrowth. For all patients, the most severe stages of epithelial ingrowth observed on slit lamp photographs correlated to the highest densitometry readings, with peak densitometry ranging from 73.3 - 95.1. These values were much higher than pre-operative densitometry readings, which ranged from 21.8 - 27.2. In two cases, the Pentacam densitometry map revealed progression of ingrowth towards the visual axis that was only faintly detectable or not detectable at all on corresponding slit lamp photographs. Corneal densitometry can be used as an objective measure of the severity and progression of epithelial ingrowth.

Thesis (Ph. D.)--University of Texas at Austin, 2001. / Vita. Includes bibliographical references. Available also from UMI Company.

There has been a strong international interest in using pyroprocessing to close the fast nuclear reactor fuel cycle and reprocess spent fuel efficiently. To commercialize pyroprocessing, safeguards technologies are required to be developed. In this research, the use of Self-Interrogation Neutron Resonance Densitometry (SINRD) has been investigated as a method to safeguard the process and more precisely quantify the 239Pu content of pyroprocessing materials. This method uses a detector array with different filters to isolate the low-energy resonance in 239Pu neutron fission cross section. The relative response of the different detectors allows for the quantification of the amount of 239Pu in the pyroprocessing materials. The Monte-Carlo N-Particle (MCNP) code was used to design a prototype SINRD instrument. This instrument is composed of a neutron source pod and a SINRD detector pod. Experimental measurements were also performed to validate the MCNP model of the instrument. Based on the results from simulations and experiments, it has been concluded that the MCNP model accurately represents the physics of the experiment. In addition, different SINRD signatures were compared to identify which of them are usable to determine the fissile isotope content. Comparison of different signatures allowed for reduction in the uncertainty of the 239Pu mass estimate. Using these signatures, the SINRD instrument was shown to be able to quantify the 239Pu content of unknown pyroprocessing materials suitable for safeguards usage.

The effects of the rate of distraction and of local infusion of IGF-1 upon bone deposition during mandibular distraction osteogenesis was studied in a rabbit model. Five groups of rabbits were studied. All rabbits, except sham operated controls, underwent distraction to 15 mm. The variables studied were the rate of distraction (0.5 mm twice a day versus 1.5 mm twice a day) and the effects of local IGF-1 infusion via osmotic infusion pumps. Analysis by DEXA scanning and three point bending 28 days after the end of distraction demonstrated no difference in density or strength of bone between the experimental groups. Histological examination demonstrated non-union across the distraction gap to be more common in rapidly distracted rabbits. Histomorphometric analysis demonstrated higher mineral apposition rates and less un-mineralised osteoid with slow as opposed to rapid distraction (p = 0.0001). Infusion of exogenous IGF-1 also resulted in a small increase in mineral apposition rate which was significant at slow but not a rapid distraction. Bone densitometry and three point bending results did not reveal any effect of distraction rate or IGF-1 infusion other than greater stiffness associated with IGF-1 infusion during rapid distraction (p = 0.01). It seems probable that the overwhelming stimulus to new bone formation produced by distraction renders the anabolic effects of IGF-1 less significant making it detectable by only the more sensitive analysis. This may be due to maximal stimulation of IGF-1 production by slow distraction thus rendering the administration of exogenous IGF-1 relatively superfluous. Rapid distraction may produce less stimulus to growth factor synthesis or the level of production maybe insufficient to cope with a higher requirement. The complete union of rapidly distracted rabbits who received exogenous IGF-1 may be as a result of levels being restored to optimal.

Thesis (Ph. D.)--University of Hong Kong, 2008. / Includes bibliographical references (p. 163-184) Also available in print.