Browsing by Subject "Radial"

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    The effect of radial convection on cell proliferation Iin bone tissue engineering
    (2009-04) Shao, Weiru
    Large bone defects are frequently encountered during surgeries. Traditional methods of repair are limited by bone graft availability and increased surgical morbidity. Tissue engineered bone tissue has many clinical advantages. However, its current technology is limited by implant size and lacks of immediate nutritional perfusion once the tissue is implanted. Objective: To sustain cell growth and proliferation in a three-dimensional scaffold unit with radial convective flow. Material and Methods: Fetal rat calvarial cells were harvested and loaded into 1x1 cm hydroxyapatite cylinders. Microperforated hollow fibers were placed at the center of the cylinders to generate radial convective flow with oxygenated cell culture medium under hydraulic pressure. Live cell densities within the blocks were determined after 8 days of convection. Results: Radial convection sustained cell growth and proliferation better than simple diffusion at all three zones of the cylinders: center, outer, and rim. Conclusion: Radial convective flow is capable of supporting cellular function and proliferation in small scaffold units. The design of the radial convection units and their system parameters are validated by this study. The results are very useful to devise future tissue engineering studies involving radial convective flow.
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    The Hexadehydro-Diels–Alder (HDDA) Enabled Synthesis of Elaborated Polycyclic Aromatic Compounds
    (2022-02) Lee, Daniel
    Polycyclic, highly fused/conjugated aromatic organic compounds (PACs) have intrigued chemists since the discovery of naphthalene in 1821. Given the unabated interest in such molecules, the development of new methods and strategies for the practical synthesis of PACs having new structural motifs is important. The advantage of thermally generating benzynes via the cycloisomerization of a tethered tri-yne (the hexadehydro-Diels–Alder reaction) serves as an excellent platform for chemists to discover new modes of benzyne reactivities and new synthetic approaches. This thesis describes a new complementary strategy to synthesize polycyclic aromatic products from multi-ynes via the HDDA reaction. Two aspects of the application of the HDDA reaction are discussed: (1) reaction of coumarins with HDDA-benzyne, and (2) construction of structurally complex molecular architectures via radial HDDA reactions.