Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 34 for “"photoactivation"”.
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Model Compounds for the Photoactivation of Glycosyl Donors
Nature exhibits complex arrays of carbohydrates in many different forms. Carbohydrate chemists still face many challenges in the synthesis of these complex substrates. This project aims to offer carbohydrate chemists a novel way of activating the anomeric position of a sugar by light to promote …
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Carbon-Carbon Bonds Formed by Lewis Acid Catalysis or Photoactivation
… to the synthesis of natural products. Finally, photoactivation of tosylhydrazones can allow for C–C bond formation when paired with organoboronates. This reaction was probed and the mechanism of photoactivation was elucidated.
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Novel applications of a 4-DMAP-derived organic electron donor under photoactivation
… group. The research programme focuses on the photoactivation of the donor 1 and its novel applications in achieving more demanding electron-transfer reactions. Chapter Two highlights the enhanced reducing power of the donor 1 under photoactivation. The reduction of the most challenging …
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SYNTHESIS, CHARACTERIZATION AND EVALUATION OF BIOACTIVE MOLECULES LINKED TO PHOTOREMOVABLE PROTECTING GROUPS FOR SPATIO-TEMPORAL CONTROL OF THEIR ACTIVITY THROUGH PHOTOACTIVATION
Biological processes are highly complex phenomena governed by a series of precise spatio-temporal events. Among the most innovative approaches developed over the last decade to investigate such processes, photopharmacology has emerged as a powerful tool, as it exploits light to control biological …
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Peptide/Protein Stapling and Unstapling: Introduction and Photorelease of Isobutylene Graft
… in vivo. The last part of the thesis describes a photoactivation decaging method of isobutylene-caged thiols through a UV-initiated thiol-ene reaction. The method was demonstrated with an isobutylene-caged cysteine, cyclic disulfide-peptide, and thiol-containing drug, all of which were rapidly and …
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Examination of a system for the mechanistic study of tumor cell-platelet interactions under well-defined flow conditions
… the 445 nm excitation wavelength revealed that photoactivation was stimulating the tumor cells and that the cells were relatively nonthrombogenic in absence of the light over the time scale of the flow experiments. Preactivation of the tumor cells was attempted with 12(S)-HETE, thrombin, and …
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Effects of glycosylation on the structure and fibrillization of prion protein fragments
… fragment as a soluble monomeric species until photoactivation, which triggered the peptide self-assembly.
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Broadening the scope of reactivity for neutral organic electron donors
… the reductive bond cleavage of various σ-bonds. Photoactivation of donor A (to A*) has been discovered to increase the reducing power of the species therefore allowing the reduction of less activated bonds and this body of work explores examples such as: carbon-nitrogen bonds of benzyl …
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Towards the development of a visible light-enabled histidine-selective protein modification strategy using diazo sulfonium-based probes
… supplemented by the temporal control of its photoactivation step. However, the UV irradiation required for reagent activation and non-selective reactivity of the generated intermediates often results in low photo cross-linking yields and numerous off-target reactions. Therefore, the …
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The chemistry of transition metal complexes related to solar energy storage : H₂ production and small molecule (CO₂ and HX; X = Cl, Br) chemistry.
… of H₂ from Ni hydride complexes, and photoactivation of Ni-Cl bonds were studied. CO₂ can be utilized as a carrier of H₂ by the syntheses of liquid fuels from CO₂ and H₂. The challenge of using CO₂ as a precursor for organic molecules is the activation of strong O=CO bonds. The …
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Design, Synthesis, Photochemical and Biological Evaluation of Novel Photoactive Molecular Switches
… in their structure. Moreover, the off/on photoactivation of the cytotoxicity was achieved, allowing us to localize the cytotoxic action in a specific part of the body. This thesis is divided into different chapters. First, a brief introduction is presented, which deals with a short …
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An Anion Selective Aminocyclodextrin Ion Channel: Ion Selectivity, pH Sensitivity and Potential as a Scaffold for Light Gating
… been developed as a potential trigger for the photoactivation of the ion channel. The utility of the tether was demonstrated by functionalizing primary, secondary and benzylic alcohols with the tether and subjecting the resulting ethers to photolysis. The photolysis of the tethered ethers was …
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Statistical image analysis of photoactivated localization microscopy
… the diffraction limit. After thousands cycles of photoactivation, most of fluorescent molecules are photoactivated and localized to super resolution. Image was constructed based on all the fitted image to form the final super resolution image. The limitation of this technique is that you have to …
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The dynamics and regulation of actin filaments in vascular endothelial cells and in a reconstituted purified protein system
… can be analyzed with PAF at long times following photoactivation. By increasing the width of the photoactivated band, actin filament turnover (t ~ 8 hours) can be distinguished from actin filament diffusion. Proteins believed to stabilize actin filaments against depolymerization markedly slow …
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Plasmon Directed Chemical Reactivity and Nanoparticle Self-Assembly
… (SAM) on gold and silver surfaces. After photoactivation, this SAM becomes positively charged at low pH, allowing it to electrostatically bind with negatively charged gold nanospheres (or other negatively charged nanoparticles). In this thesis, I describe both a secondary photoreaction …
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Dopamine-dependent Transcriptional Dynamics in Striatal Physiology and Cocaine Reward
… expressing channelrhodopsin, we demonstrate that photoactivation of MSNs in the NAc core is sufficient for reward-seeking behavior, independent of cocaine. In order to better characterize the cell populations driving these physiological and behavioral adaptations to cocaine, we employed snRNA-seq …
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Photodynamically Activated Multifunctional Chitosan Nanoparticles to Disinfect and Improve Structural Stability of Dentin
… structure. The singlet oxygen generated during photoactivation produced photochemical crosslinking of dentin collagen and infiltration of chitosan nanoparticles. Following crosslinking the dentin collagen showed significantly improved mechanical properties (ultimate tensile strength and …
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Two-Photon Microscopy of E-Combretastatin uptake and activation in live mammalian cells
… light to trigger a nonlinear two-photon excited photoactivation process provides deeperlight penetration into tissues and minimizes cellular autofluorescence compared withUV/visible light.The work described in this thesis is highly multidisciplinary. A major task was the synthesisof a range of …
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Synthesis and evaluation of novel antivascular agents for two-photon activation
… light to trigger a nonlinear two-photon excited photoactivation process provides deeper light penetration into tissues. This thesis describes the synthesis and characterisation of a range of combretastatin derivatives with improved two-photon cross sections as target compounds for two photon …
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