Made available in DSpace on 2014-06-11T19:30:29Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-12-19Bitstream added on 2014-06-13T20:00:44Z : No. of bitstreams: 1 silva_ae_dr_botfm.pdf: 677283 bytes, checksum: 81300198b62fe55885f8b966cdd716bf (MD5) / Os anestésicos inalatórios halogenados podem apresentar papel importante na patogênese das alterações cardiocirculatórias e renais durante o choque hemorrágico por alterarem, de maneira dose dependente, os mecanismos de defesa compensatórios. O presente estudo teve como objetivo comparar os efeitos de uma concentração alveolar mínima (CAM) de halotano, sevoflurano e isoflurano sobre o sistema cardiovascular e renal em cães submetidos a choque hemorrágico e reposição volêmica com o sangue retirado do animal. O estudo aleatório foi realizado em trinta cães, sem raça definida, distribuídos em três grupos de acordo com o anestésico inalatório halogenado utilizado durante a anestesia, em concentrações eqüipotentes de uma CAM: GH (n=10) - halotano a 0,89%; GS (n=10) - sevoflurano a 2,4%; e GI (n=10) - isoflurano a 1,4%. Todos os cães foram ventilados mecânicamente, esplenectomizados e submetidos a sangramento, com retirada em torno de 40% do volume sangüíneo, visando manter a pressão arterial média de 40 a 50 mm Hg durante 45 minutos. A seguir, os cães foram submetidos à expansão volêmica com o sangue removido. Os atributos hemodinâmicos foram determinados no momento controle, após 45 minutos de hemorragia, e 15 e 60 minutos após a reposição sangüínea. Os atributos renais foram medidos nos mesmos momentos, exceto no período hemorrágico, pela ausência de diurese. No momento controle, a maioria das variáveis hemodinâmicas e renais foram semelhantes entre os grupos, com exceção da fração de filtração, cujos valores foram menores no grupo GI, em relação aos grupos GH e GS (p < 0,05), e da osmolalidade urinária, cujos valores foram maiores no grupo GS, em comparação com o grupo GH (p < 0,05). Após a hemorragia... / Halogenated anesthetics may play an important role in the pathogenesis of cardiovascular and renal changes during hemorrhagic shock because they modify, in a dose-dependent manner, compensatory defense mechanisms. The aim of the present study was to compare the effects of a minimum alveolar concentration (MAC) of halothane, sevoflurane and isoflurane on the cardiovascular and renal systems of dogs subjected to hemorrhagic shock followed by restoration of blood volume with shed blood. Thirty mongrel dogs were randomly distributed into three groups according to the halogenated anesthetic used for anesthesia. They were anesthetized with halothane (H group; n=10), sevoflurane (S group; n=10) or isoflurane (I group; n=10) and anesthesia was maintained at 1.0 MAC: 0.89%, 2.4%, and 1.4%, respectively. All the dogs were mechanically ventilated, splenectomized and subjected to bleeding with 40% blood reduction to keep mean arterial pressure between 40 and 50 mm Hg for 45 min. Thereafter, the dogs were resuscitated with shed blood. The hemodynamic attributes were determined at the control moment, after 45 min of hemorrhage, 15 and 60 min after restoration of blood volume. The renal attributes were determined at the described moments, except during the hemorrhage period, for lack of diuresis. At the control moment, most of the hemodynamic and renal variables were similar among the groups, except for the filtered fraction, Introdução e Literatura 11 which was lower in GI than in groups GH and GS (p < 0.05), and for urinary osmolarity, which was higher in GS compared to GH (p < 0.05). After hemorrhage, the hemodynamic attributes decreased, without significant differences among the groups (p > 0.05). Fifteen minutes after resuscitation, most of the hemodynamic and renal attributes were... (Complete abstract click electronic access below)

A time-resolved holographic interferometer specially suited for high-speed visualization of the gas flow in shock tube experiments has been developed. Holographic interferometry, which is based on the recording of two coincident holograms at different times so that one of them acts as a reference field, can accurately reveal the density distribution in a gas. The device described here fills the need for a practical method to record short sequences of holographic interferograms documenting the evolution of shock wave reflections that are not self-similar in time. Multiple hologram recording was implemented on an existing holographic interferometric system through the technique of spatial frequency multiplexing, in which the holograms are overlaid but the reference beam is angled differently for each exposure. Because the object beam is not involved in the multiplexing process, the imaging optics of the original system could be left unmodified. The upgrade only entailed the introduction of an angular sweeping system in the reference beam path. The beam multiplexing assembly was initially based on a spinning mirror design, which produced fairly satisfactory recordings of non-interferometric holographic sequences but was incapable of accurately overlaying a second set of exposures establishing the reference field for each image. The mechanical sweeping system had other drawbacks as well, among them the tendency to create extraneous fringes in the holographic images because of the unavoidable angular motion of the reference beam over the duration of a laser pulse. A solid-state multiplexing system was then devised in which the reference beam was split into several branches, each aimed at the film from a different direction and individually shuttered by a ferroelectric liquid crystal light valve. Beam sweeping was achieved by opening the shutters in sequence as the laser was pulsed, but it was also possible to record the reference exposure on all images simultaneously with a single laser pulse by having all shutters open at the same time. A prototype three-image system was constructed and successfully tested by recording interferometric sequences of a shock wave reflecting off a model at framing intervals down to 100 μs. / Graduate

学位授与大学：京都大学 ; 取得学位: 博士(工学) ; 学位授与年月日: 2007-09-25 ; 学位の種類: 新制・課程博士 ; 学位記番号: 工博第2859号 ; 請求記号: 新制/工/1420 ; 整理番号: 25544 / Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第13388号 / 工博第2859号 / 新制||工||1420(附属図書館) / 25544 / UT51-2007-Q789 / 京都大学大学院工学研究科精密工学専攻 / (主査)教授 松久 寛, 教授 吉村 允孝, 教授 松原 厚 / 学位規則第4条第1項該当

In this thesis I present complex experimental data on the physiological and molecular adaptations during diapause development and overwintering in a linden bug, Pyrrhocoris apterus (Heteroptera, Pyrrhocoridae). I focus on adjustments of the enzymatic complement, which is involved in the biosynthesis of cryoprotectants, and heat shock proteins, which are expressed in response to temperature stress.

Cavitation is the formation of vapour filled bubbles in a liquid. They can be generated either by the reduction of the ambient water pressure at constant temperature or by a temperature increase at constant pressure. In the results of the experiments presented in this work a range of different diameter cavitation bubbles were generated by focusing pulses of near IR radiation (le = 1064 nm) from a Q-switched Nd:YAG laser of varying energy in a small water tank. Single exposure high speed shadow photography and Schlieren techniques are used to visualise the oscillating motion of the cavitation bubbles with high temporal and spatial resolution. The optical analysis of the cavitation bubble in free water shows a smooth symmetrical oscillating motion during the first cycle. When the bubble is collapsing near a solid boundary the motion becomes asymmetrical. The Schlieren images in combination with matching plots of a thin film polyvinylidene fluoride (PVDF) pressure transducer confirm the formation of a liquid jet as well as different shock wave emissions for certain bubble to boundary parameters. They also indicate the importance of the resulting fluid flow to stresses induced in the solid boundary. In an attempt to visualise the fluid flow field around an oscillating cavitation bubble the IR laser radiation is focused in a solution of copper sulphate (CUS04) for contrast enhancement. High speed photography in combination with an accurately positioned Schlieren knife edge displays the heated path of the laser beam and the different shapes of the cavitation bubble. For the case of a bubble in free space the marked laser path indicates radial fluid flow only. For a bubble in front of a solid boundary the marked laser path clearly shows the motion of the fluid into the toroidal shaped bubble during the collapse process. For this case the marked paths are similar to numerically calculated streamline plots. In contrast to the solid boundary a flexible boundary was also used. The interaction of the cavitation bubble with the flexible boundary visualises partially the movement of the water but is found to still destroy some of the symmetry of the bubble.

Ph.D. / Heat shock proteins (HSP) (in particular hsp70) are increasingly synthesised during and following exposure to stressful insults, playing an important role in protection and adaptation. Protective effects of HSP concerning infection and immunity include self/non-self discrimination, enhancement of the immune response, immune protection, thermotolerance and cytoprotection from inflammatory mediators (reactive oxygen species and cytokines). Considering the general protective role of hsp70 and its specific immunological functions, including antigen processing and presentation, variation in hsp 70 genes may contribute towards differential coping with stress and disease susceptibility. In humans, three members of the hsp70 gene family, hspl0-1, hsp70-2 and hsp70-hom, were mapped to the MHC class Ill region approximately 280 kbp centromeric to the TNFa gene and 92 kbp telomeric to the C2 gene. Polymorphisms in MHC-Iocalized hsp70 genes have been implicated in susceptibility to a number of diseases, independently or in combination with class II polymorphisms due to linkage disequilibrium (LD). MHC alleles are most often associated with immunosuppressive diseases. Tuberculosis (TB) has a strong immunological basis, involving cell-mediated immunity with human leukocyte antigen (HLA) variants implicated in its susceptibility/resistance. In the light of the above, the role of hsp70 polymorphism in TB susceptibility, alone or in combination with MHC class II alleles, was investigated through the following objectives: 1) Typing of hsp70 gene polymorphism (hsp70-1, hsp70-2 and hsp70-hom) in controls and TB cases from the Cape Coloured population of South Africa 2) Comparison between Cape Coloureds and Caucasoid populations with regard to hsp70 allele and genotype distribution 3) Studying linkage disequilibrium between members of MHC class II (HLADRB1) and Ill (hsp70) alleles in the Cape Coloureds 4) Simulation of MHC class II and Ill haplotypes in this particular population Hsp70 polymorphism was studied in controls (n=106) and TB cases (n=107) from the complex hybrid Cape Coloured population inhabiting the Western Cape region of South Africa - a population showing increased susceptibility to TB. PCR-RFLP and PAGE analysis were used to determine the hsp70 allele frequencies and genotype distribution of the individuals studied, while linkage disequilibrium between MHC class II and Ill, and within class Ill alleles, was investigated using the software "Graphical Overview of Linkage Disequilibruim" (GOLD). Haplotypes comprising MHC class II and Ill alleles were simulated using the software PHASE.

The need to monitor fresh water ecosystems for pollution is increasing, as is the need to develop a biomarker sensitive to a range of environmental insults. Recently, heat shock proteins have been identified as possible biomarkers of environmental contamination. However, evaluation as to their use as a biomarker of metal contamination in fish species endemic to Southern Africa is limited. The purpose of this study was to identify what members of the 70 kDa family of heat shock proteins (Hsp70) were present in the liver of Oreochromis mossambicus, and if their accumulation was altered after short-term (96 hour) exposure to aqueous copper. In addition to copper exposure, the effect of acclimation media was also examined. Tissue-level analysis was done by means of histological examination so as to determine if alterations in the accumulation of the Hsp70 family had a marked effect on the structural integrity of the liver. Specimens of Oreochromis mossambicus acclimated in either aged tap water or borehole water were placed in flow-through systems and exposed to either 10% or 20% of the LC50 value of cupric chloride for a duration of 96 hours. Control groups were run in conjunction with the exposure groups so as to set control values by which to compare. Heat shock protein analysis was done by Western blotting after separation of hepatic proteins by SDS-PAGE. For the purpose of histological analysis, representative samples were randomly selected. Analysis of the hepatic heat shock protein 70 family identified the presence of three (3) members, each of a different molecular weight. These included members of 70 kDa (Hsp70), 74 kDa (Hsp74) and 76 kDa (Hsp76). In addition to these findings, it was found that Oreochromis mossambicus accumulated high levels of particular members of the heat shock protein 70 family under unstressed conditions, affording the fish adaptability to environmental extremes. Furthermore, individuals acclimated in aged tap water showed decreased Hsp76 accumulation after exposure to sub-lethal copper concentrations, whereas those individuals acclimated in borehole water retained relatively high levels of Hsp76. Additionally, it was shown that the hepatic structure deteriorated in those individuals acclimated to the aged tap water after copper exposure, with observed increases in vacuolation, number of macrophage centres present and the occurrence of intracellular golden-brown granules. However, there was little change from the already-altered hepatic structure of those individuals acclimated in borehole water, with conspicuous golden-brown granules the most obvious histopathological condition present. Histological examination therefore proved to supplement the heat shock protein results obtained. This study thus concluded that a decrease in the accumulation of the Hsp70 family resulted in a negative organismal response, initiating deleterious alterations in the hepatic structure. Additionally, this study concluded that past water quality has a marked effect on a given biomarker response, and should be taken into careful consideration when conducting biomarker studies. / Prof. J.H.J. Van Vuren

No description available.

This thesis investigated the shock compression and fragmentation of ge- ological materials with application to blast mining. Two geological materi- als were investigated; Lake Quarry Granite and Gosford Sandstone. Lake Quarry Granite was fully dense, while Gosford Sandstone was porous. The composition and microstructure of the materials were quanti ed and this information was later used in the analysis of their mechanical properties. The elastic sound speeds were measured for each material, from which their elastic moduli were derived. Gosford Sandstone had a reduced sound speed compared to its component minerals, which was analysed using geometric grain models and Hertzian contact theory. The shock Hugoniot of each ma- terial was measured though a series of plate impact experiments using a light gas gun. The experiments focused on the stress region of interest for blast mining, 0 to 12 GPa. The, fully dense, Lake Quarry Granite was found to have a constant shock speed, which agreed with the elastic longitudinal sound speed measured previously. As the material remained elastic, its Hugoniot was shown to be predictable using composite theory and the chemical com- position. The, porous, Gosford Sandstone underwent shock compaction and resulted in large variations in shock speed. The Hugoniot of Gosford Sand- stone was found to remain partially porous, even to high stresses, and was analysed using a P-a shock compaction model. Explosively-driven expanding ring fragmentation experiments were performed on Lake Quarry Granite to observed its fracture response under loading similar to those in blast mining. The experiments established that the fragment size reduced with loading strain rate until it reached the grain size. After this point the fragment size remained constant with increasing strain rate, a phenomenon not previously observed. The rock was found to be dominated by intergranular fracture, so the minimum achievable fragment size was the size of the grains with this failure mechanism.

The dynamic response of various geological materials has been investigated through a series of plate impact experiments. The materials involved were supplied from various mines by De Beers and Rio Tinto and were generically termed: sandstone, scilified siltstone, kimberlite, quartz/feldspathic gneiss, biotite schist, amphibolite, amphibolitic gneiss, basalt and iron ore. Investigations into compressional, shear and tensional behaviour were carried out. This project was part of a larger international study to develop models for the explosive loading of rock in a mining environment. This model is known as the Hybrid Stress Blasting Model, or HSBM. For this model to be accurate and relevant to the mining process it is essential to have dynamic data on the various rock types concerned. This was the purpose of the current project. As the material data are destined for use in a computer modelling programme it was essential to attempt to develop prediction methodologies to avoid the need for expensive dynamic characterisation of any new materials encountered in the mining environment. Much of the static data provided with the materials from De Beers proved of little use in predicting behaviour, although crucially it was not possible to determine sufficient dynamic tensile strengths in this investigation to make comparisons with the De Beers data. More success was found in predicting the slope of the Hugoniot with the elastic impedance of the material (for the non-porous linear Hugoniot materials). A fairly strong trend was found, which was backed up with data from the literature. Additionally some effort at further analysis using mineral data was undertaken. Attempts at predicting the HEL were also partially successful. While no specific quantitative prediction method was found, it was noted that the HEL did seem to scale with grain size, in that the large grained materials had a lower value of the HEL (below 2 GPa) compared with the finer grained materials (around 4 GPa and above).