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 61 for “"hyperpolarization"”.
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Making Nuclear Magnetic Hyperpolarization Practical through Storage in Disconnected Eigenstates
… before the system return to equilibrium. Hyperpolarization methods solve the problem of signal amplitude, however, the duration of the hyperpolarized signal is still limited by the spin-lattice relaxation time, T1. Disconnected eigenstates provide a mechanism by which hyperpolarization can …
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Clinical-Scale Hyperpolarization of 129Xe and 131Xe via Stopped-Flow Spin Exchange Optical Pumping
The fundamental physics of spin-exchange optical pumping (SEOP) has been explained in detail by many brilliant scientists since its discovery in the 50’s and 60’s. Although some interactions remain only tenuously understood, mathematical relationships have been mapped across many trajectories with …
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Vasopressin decreases excitability in rat lateral amygdala neurons through inhibition of hyperpolarization-activated cationic current.
… a decrease in action potential accommodation and hyperpolarization-activated current (Ih) amplitude in LA pyramidal cells. OT exerts complementary effects, causing an increase in action potential accommodation and Ih amplitude, resulting in decreased excitability. These results suggest AVP and OT …
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The role of hyperpolarization-activated non-selective cation current in amygdala excitability and serotonin mediated effects.
The hyperpolarization-activated, cyclic nucleotide-dependent non-selective cationic (HCN) current (Ih) has an important functional role in the rat brain, participating in network oscillations, temporal summation of synaptic inputs, and seizure development. Since hyperexcitability of the amygdala is …
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Cobalt catalysts towards parahydrogen induced polarization
… py = pyridine] , towards hyperpolarization of substrates via PHIP chemistry. In Chapter 2, the development of structural and electronic variants of the CCC ligand platform is discussed. The synthesis of a chiral ligand and a tolyl variant is achieved through modification of …
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An Intramural, Tension-modulating Reflex in the Rat Caudal Artery
… inhibition of K<sub>Ca++</sub>-dependent hyperpolarization with tetraethylammonium (TEA), or K<sub>ATP</sub> hyperpolarization with BaCl<sub>2</sub> or glibenclamide also reduced EFS-induced relaxation. L-arginine reversed the effect of L-NAME. When either MB and KCl, L-NAME and KCl, or …
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Electronic simulation of an associative neuron
… (depolarization), and postsynaptic inhibition (hyperpolarization). The simulation presented uses a single 12 volt power supply, operates on pulses which swing in the negative direction, has a high input impedance and a low output impedance, may be easily modified to adjust the response …
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Sign-Inverting Vectors Underlie a Coordinate Transformation in the Drosophila Central Brain
… Wind from the back, however, is signaled with hyperpolarization of the PFNa neurons, which induces a non-canonical, prominent, 2-6 Hz membrane potential oscillation, reminiscent of mammalian delta rhythms. These membrane potential oscillations drive a calcium response in the PFNa cells that …
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Modulation of Hypoglossal Motoneurons by Nitric Oxide
… but not the time-dependent component of the hyperpolarization-activated current (Ih) generated by hyperpolarization-activated cyclic nucleotide gated (HCN) channels. These results suggest that sleep-induced nitrergic innervation of the HMN helps compensate for respiratory motoneuron …
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Development of Magnetic Resonance Spectroscopic Imaging Methods to Assess Tumour Metabolism
… Sensitivity can be increased by transferring the hyperpolarization to spin coupled protons provided that there is not significant polarization loss during the transfer. To exploit both the slow relaxation offered by storing the hyperpolarization in the low gamma nucleus and the higher sensitivity …
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Development of pulse sequences for hyperpolarized 13C magnetic resonance spectroscopic imaging of tumour metabolism
… in vivo. However, the transient nature of the hyperpolarization - and its depletion following excitation - limits the imaging time and the number of excitation pulses that can be used. A single-shot 3D imaging sequence has been developed and it is shown in this thesis to generate 13C MR images …
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An Automated Syringe Pump System For Improving The Reproducibility of Dynamic Hyperpolarized Mri Phantoms
… imaging measurements or any other method. Hyperpolarization is achieved through dynamic nuclear polarization. This is a process in which a sample is quickly frozen to near absolute zero (~1.4K), and placed in a strong magnetic field. In these conditions, magnetization in unpaired electrons, …
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Modulation of the Magnetic Properties of Aqueous Metal Ions and the Bioelectrodynamic Effects on Cancerous and Noncancerous Cells
… growth inhibition, cell cycle arrest, hyperpolarization of transmembrane potential and apoptosis of cancerous cells while not causing a growth inhibition, cell cycle arrest or apoptosis of the noncancerous cell lines. Microarray and RT-qPCR show the cancerous cells headed to apoptosis …
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AMPK-MEDIATED LONG-TERM REGULATION OF HCN4CONTRIBUTES TO AGE-RELATED SINUS BRADYCARDIA
Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels mediates inward depolarizing currents, called If in the heart and Ih in the brain, that contribute to the regulation of neuronal excitability and cardiac rhythm. Among the HCN isotypes, HCN4 stands out for its prominent role in …
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Cholinergic Control of Cortical Circuit Activity
… supragranular layers, and muscarinic-mediated hyperpolarization of excitatory cells in layer 4. Together, these findings present novel circuit mechanisms for fast and robust cholinergic signaling in neocortex.</p>
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Cellular Mechanisms Underlying the Action of Melatonin in the Suprachiasmatic Nucleus
… that could be modulated by melatonin is the hyperpolarization-activated current(Ih). Ih is a mixed Na+/K+ inward current that plays an important role in the regulation of SCN neurons excitability by limiting the duration of hyperpolarizing events. The mammalian hyperpolarization-activated and …
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