Indiana University-Purdue University Indianapolis (IUPUI) / Biological cells are constantly subjected to mechanical forces such as tension, compression and shear. The importance of these forces in mediating cell signals, maintenance of lineages, promoting embryonic cell differentiation and tissue engineering is only now coming into focus. It has been shown that stretch stimulus can influence growth, differentiation, as well as tissue strength and integrity. Most stretch systems built to understand more of these phenomena suffer from shortcomings, as accurately replicating the in vivo environment is quite challenging. Many of the devices currently available are very expensive as well as limited to a single application. The objective of this thesis is to design, manufacture, test, and validate a novel uniaxial cyclic cell stretch device that overcomes most of the major limitations of existing systems, and to experimentally demostrate that uniaxial cyclic stretch causes a shift towards in vivo characteristics of smooth muscle cells. The stretch mechanism is driven by a single servo motor which makes its operation simple and straight forward. Coolworks Lite, a proprietary software of the servo motor supplier, is used to control the motor and LabVIEW is used to obtain feedback from the sensors. Validation for the stretch machine was done by evaluating the performance of the device against engineering requirements. Methods were suggested to improve shortcomings that were encountered. Also, the machine's unique design allows its extension to a biaxial stretch unit while keeping the same driver platform, a concept for which has been discussed and illustrated.

This dissertation research is based on two reactions, including those of cyclic ketene acetals with acid chlorides and acid catalyzed olefination reactions in bio-oil. In first four chapters, reactions of in situ generated cyclic ketene acetals were explored. Highly functionalized heterocycles such as pyrrollo-[1,2-c]imidazolediones, were synthesized in one-pot reactions of 2-alkylimidazoles or 2-methylbenzimidazoles with 1,3-diacid chlorides. Some reactions proceed through in situ generated cyclic-N,N′-ketene acetal intermediates. 2-Alkylimidazoles and 2-methylbenzimidazole can be considered as tridentate nucleophiles in these reactions that can give four consecutive attacks on electrophiles which ultimately generate new heterocycles. Reactions of substituted oxazoles and thiazoles with different acid chlorides in the presence of different bases were explored. Arylvinyl esters of substituted benzoic acids containing substituted oxazoles or thiazoles were formed when aroyl chlorides were used. Most reactions occurred through in situ generated cyclic ketene acetals. Reactions of 2-methylbenzoxazole and 5-phenyl-2-methylbenzoxazole with acid chlorides and base in THF generated a series of ortho-amidoesters. All of these reactions showed that aromatic heterocycles based in situ generated cyclic ketene acetals could be used to make highly functionalized heterocycles under mild conditions. These one-pot reactions generated various heterocycles, which might have useful bioactivities. For example, arylvinyl esters of substituted benzoic acids have been reported to show insecticidal activities. The last two chapters describe the olefinations of bio-oil and model bio-oil compounds using acid catalysts. Two different branched olefins were used, representative of those available at petroleum refineries. Amberlyst-15 and Nafion NR-50 were used as heterogeneous acid catalysts. The acid catalyzed olefination of bio-oil was explored using an excess of 1- octene. Some olefinations were performed in the presence of ethanol. Ethanol was used to make the olefin and bio-oil phases partially miscible. Acid catalyzed olefination of raw bio-oil induced some changes in the resulting bio-oil by generating variety of alcohols, ethers and oligomeric mixtures of the starting olefin. Olefination with excess 1-octene showed the decrease of the water content and the acid value and increase of the heating value of the bio-oil. Thus, the acid catalyzed olefination of bio-oil can be considered as a potential bio-oil upgrading technique.

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Maximal unramified extensions of quadratic number fields have been well studied. This thesis focuses on maximal unramified extensions of cyclic cubic fields. We use the unconditional discriminant bounds of Moreno to determine cyclic cubic fields having no non-solvable unramified extensions. We also use a theorem of Roquette, developed from the method of Golod-Shafarevich, and some results by Cohen to construct cyclic cubic fields in which the unramified extension is of infinite degree.

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Novel bifunctional five-membered cyclic dithiocarbonates (1,3-oxathiolane-2-thione)s were synthesized by the reactions of the corresponding bifunctional oxiranes (epoxides) with carbon disulfide at room temperature with lithium bromide as catalyst. Full characterization of these monomers was performed including elemental analysis, proton and carbon nuclear magnetic resonance (NMR) spectroscopy, gas chromatography-mass spectroscopy, and Fourier transmission infrared (FTIR) spectroscopy. The polyaddition polymerization of 1,3-oxathiolane-2-thione with 1,4-diaminobutane at room temperature resulted in a poly(thiourethane) material. The latter undergoes crosslinking due probably to the autooxidation of the product and formation of disulfide linkages. The five-membered cyclic dithiocarbonate, 5-decyl-1,3-oxathiolane-2-thione, was used a model to demonstrate the usefulness of five-membered cyclic dithiocarbonates for the preparation of compounds bearing thiol and thiocarbamate groups. This functionality was desired for use as metallic nanoparticle stabilizers. A thermal decomposition oxidation method was used to synthesize the magnetic iron nanoparticles. The stabilized magnetic nanoparticles were characterized by transmission electron microscopy (TEM) to determine the shape and the size of the nanoparticles. Energy dispersive spectroscopy (EDS) was used to analyze the composition of the magnetic nanoparticles.

Previous research has provided evidence in support of apoptotic osteocytes playing a role in the bone remodeling process. In this study, we examined the regional and quadrantal variations of apoptotic and viable osteocytes in cyclically loaded and unloaded samples. Left tibias of C57 Black 6 Taconic mice (C57Bl/6) were cyclically loaded for either 2 weeks or 5 weeks, with the right tibias being used as controls. After loading, tibias were resected, processed, and then stained using either a TUNEL stain, to show apoptotic osteocytes, or a 2.0% methyl green solution, to reveal viable cells. Cross-sectional images from each tibia were then captured and analyzed in each region (distal, midshaft and proximal) and quadrant (cranial, lateral, caudal, and medial) by counting the number of osteocytes, both apoptotic and viable, and subsequently calculating the percentages and densities of those osteocytes. Individual analysis of each sample group showed that the 5 week loaded bones, with the most statistically significant p-values, had the most regional variations within the samples, specifically showing decreased apoptotic and viable osteocytes in the lateral quadrants. Comparative analysis revealed a statistically significant higher percentage and density of apoptotic osteocytes in 5 week loaded samples compared to all other samples. This provides further quantitative evidence in support of apoptotic osteocytes playing a role in bone remodeling.

No / In this work we propose a modelling technique for producing cyclic motions of human body. The surface of the human body has been created from a set of pre-configured curves that were used as the set of boundary conditions to solve a number of partial differential equations (PDE). These boundary curves are attached to a skeletal system that holds the animation for cyclic motions. An important function of the method described here is the use of mathematical expressions within Maya software for generating the cyclic motion leading to a very realistic movement. Thus, the user can interactively manipulate the position and movement of various body parts to achieve various cyclic motions. Finally the animation can be transferred to either the original mesh model from where the boundary curves associated with the PDE surface were extracted or to another mesh model with equivalent topology.

<p> This thesis is a contribution to the theory of Steiner quadruple systems. The first chapter provides a construction of resolvable Steiner quadruple systems that is different from the known constructions. In the second chapter, we construct Steiner quadruple systems with an automorphism that consists of a cycle of length 2 plus a cycle of full length minus 2, and investigate the number of pairwise distinct systems of this kind. In the third chapter, we also construct non-S-cyclic Steiner quadruple systems, one of which is an answer to a question raised in [11], and also investigate the number of pairwise distinct systems.</p> / Thesis / Master of Science (MSc)