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Showing 1 to 15 of 15 for “"T1 relaxation"”.
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Tastant interactions with model membranes
… are investigated using NMR spectroscopy. The T1 relaxation times of the tastants were determined in aqueous solution and in solution with liposomes, a model membrane system. The observed changes in T1, values are analysed to determine which regions of the tastants are involved in the …
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Studies on the preparation and characterization of novel water-soluble catalysts
Spin-lattice (T1) relaxation studies using solid-state and solution-state :31p nuclear magnetic resonance spectroscopy have proven to be a reliable procedure for determining the onset of a "liquid-like" character of the supported phase in a supported aqueous phase catalyst. It has also been shown …
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Cerebrospinal fluid flow quantification in the brain using magnetic resonance imaging
… ml/min. Additionally, taking into account the T1 relaxation rate, we can fit a curve to the data points using simulations to predict the flow rate of the measured signal.
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Biological Water: Properties and Role in Muscle Function and Development
… kinetic energy, faster NMR spic-lattice (T1) relaxation and lower self-diffusion coefficient of water. The findings collectively indicate more ordered state of water near surfaces. In the second part of this work, water inside living muscle cells and intact myofibril was studied using …
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Combined NMR and simulation study of carbohydrate linkage dynamics
… reference as a check on their validity. N!vlR T1 relaxation measurements, which give indirect information on the atomic scale dynamics, have been measured for each of the model fragments and compared with values calculated directly from simulation.
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Development of new methods in solid-state NMR
… and the usual efficiency of quadrupolar T1 relaxation, respectively. In this thesis, 11B{1H} transient NOE results are presented for a range of solid borane adducts. A comparison is made of the 11B NMR enhancements observed under MAS and static conditions and a rationale is proposed for …
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Quantification Of Vascular Parametric Indices Using Dynamic Contrast-Enhanced Magnetic Resonance Imaging
… extracting contrast concentration, estimating T1 relaxation and estimating pharmacokinetic parameters.</p> <p>In this work, a new approach to used fixed T1(0) which provides more reproducible DCE results has been introduced. Using this new algorithm to quantify the vascular changes in DCE-MRI, …
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Vapour-Liquid Equilibria within Nanoporous Media
… fields of an NMR spectrometer. NMR spectroscopy, relaxation and pulsed field gradient (PFG) diffusion experiments were performed on each of the systems discussed in this report. Cyclohexane was initially studied inside a porous titania catalyst support at 188 °C and various pressures up to 13 bar. …
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Multiparametric cardiac magnetic resonance imaging with motion compensation
… diagnosed. Recently, it has been shown that T1-relaxation times can be used to characterize myocardial pathologies even if they are not localized but affect the entire myocardium (diffuse disease). Furthermore, T1 serves as a tissue specific quantitative diagnostic parameter which ensures …
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Transient Radicals Produced by Sonication and the Investigation of Paramagnetic Effects
… of free radicals can be monitored by decrease in T1 during NMR experiments due to paramagnetic effects. Our goal is to develop a method in which ultrasound is used to enhance NMR. By irradiating the sample during analytical measurements, we can decrease T1 which can be used as a non-toxic contrast …
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Synthesis and applications of core functional hyperbranched polyglycerol
… with increasing cross-link density using 1H NMR T1 relaxation times. The third chapter describes two methods for the use of polyglycerol to increase the photostability of organic dyes. The first method uses the steric bulk of polyglycerol as a protective layer to prevent interaction of the dye …
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Quantification of Myocardial Perfusion Based on Signal Intensity of Flow Sensitized MRI
… the relative difference in the apparent T1 relaxation times in response to selective and non-selective inversion of blood entering the region of interest is related to perfusion via a two-compartment tissue model. But accurate determination of T1 in small animal hearts is difficult and …
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Identification of battery products and intermediates through NMR spectroscopy
… discharge to obtain chemical shifts and T2 relaxation times of the products formed, which are discussed. The chemical shifts in the spectra of both 6Li and 33S NMR demonstrate that long-chain, soluble lithium polysulfide species formed at the beginning of discharge are indistinguishable from …
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Deformation induced molecular behavior of Cis 1,4-polyisoprene and its nanocomposites monitored by solid-state NMR
Proton spin lattice (T1) relaxation time constants were used to monitor changes in the molecular motion and architecture of polyisoprene, polyisoprene-clay composites and polyhedral oligomeric silsesquioxane (POSS) nanofillers. The high frequency relaxations monitored by NMR are sensitivity to …
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Elucidating Structure and Dynamics of Extracellular Matrix Collagen Using Solid-State NMR
… backbone motions via the use of the $^15$N T$_1$ relaxation. Further, we use U-$^13$C,$^15$N-isotopically enriched collagen ECM samples to investigate the conformational and dynamic changes after glycation of the hydrophilic and hydrophobic regions of the collagen fibrils. Finally, we propose a …