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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

Application and development of NMR spectroscopy to study the conformation and dynamics of collagen-like triple helical peptides

Li, Yingjie. January 2007 (has links)
Thesis (Ph. D.)--Rutgers University, 2007. / "Graduate Program in Biochemistry." Includes bibliographical references (p. 164-176).
72

Structural analysis of amylin and its analogs by NMR spectroscopy /

Liu, Zhihong. January 1999 (has links)
Thesis (Ph. D.)--University of Washington, 1999. / Vita. Includes bibliographical references (leaves 286-303).
73

Analysis of NMR spectra using digital signal processing techniques

Gearheart, Jason Aaron. January 2006 (has links) (PDF)
Thesis (M.Eng.)--University of Louisville, 2006. / Title and description from thesis home page (viewed Jan. 30, 2007). Department of Computer Engineering and Computer Science. "December 2006." Includes bibliographical references (p. 32-33).
74

Nuclear magnetic resonance force microscopy of ammonium dihydrogen phosphate and magnetism of cobalt nanocrystals

Mirsaidov, Utkur, January 1900 (has links) (PDF)
Thesis (Ph. D.)--University of Texas at Austin, 2005. / Vita. Includes bibliographical references.
75

Structural studies of polyoxoanionic solids by vanadium-51 and phosphorus-31 solid state magic angle spinning NMR spectroscopy

Huang, Wenlin. January 2007 (has links)
Thesis (Ph.D.)--University of Delaware, 2007. / Principal faculty advisor: Tatyana Polenova, Dept. of Chemistry & Biochemistry. Includes bibliographical references.
76

Functional annotation screening technology by nuclear magnetic resonance spectroscopy

Mercier, Kelly A. January 2008 (has links)
Thesis (Ph.D.)--University of Nebraska-Lincoln, 2008. / Title from title screen (site viewed Feb. 17, 2009). PDF text: 182 p. : ill. (chiefly col.) ; 5 Mb. UMI publication number: AAT 3328255. Includes bibliographical references. Also available in microfilm and microfiche formats.
77

The NMR properties, photochromism and efficient syntheses of several [e]-annelated dimethyldihydropyrenes

Ward, Timothy Robbins 07 August 2018 (has links)
A systematic and efficient route to [e]-annelated derivatives of 2,7-di-t- butyl-trans-10b, 10c-dimethyl-10b,10c-dihydropyrene 34 has been achieved which provides access to the benzo, naphtho, and anthro derivatives of 34, by means of a Diels - Alder reaction of an aryne with a furan. Reaction of the annulyne derived from bromide 50 with furan gave adduct 52 which could be both deoxygenated to benzo derivative 53 and reacted with tetrazine 54 to yield the annuleno furan 55 which subsequently with benzyne and 2,3-naphthalyne yielded adducts which were deoxygenated to naphtho and anthro derivatives 57 and 59. Reaction of the furan 55 with the benzoannulyne derived from 65 gave the cyclophane fused pyrene 68, while reaction of the annulyne derived from 50 with the bisfuran 62 gave the chrysene bis pyrene 60. These fused dihydropyrene derivatives are all photochromic, and the photoisomerizations were studied In each case. Dihydropyrenes 53, 57, 59, and 65 are simple photoswitches, while 60 and 68 are more complex multiple state switches. In each case the kinetics of the MOD to DMDHP reaction was followed to obtain the activation energy, enthalpy, and entropy. It was found that the activation enthalpies and energies decreased through the series, from the benzo to the naphtho to the anthro system. This suggested that the transition states for the MCD to DMDHP reactions were stabilized by resonance with the respective annelated fragments. Detailed analysis of the NMR data of all compounds yielded an experimental aromaticity scale in which δ(Me) or δ(H4) could yield information to obtain the relative resonance energy of the annelating fragment. Correlations between methyl and H4 protons were obtained and compared to related systems. / Graduate
78

Deuterium nuclear magnetic resonance in model membrane systems : an investigation of the interaction of a synthetic, amphiphilic polypeptide with charged lipids

Poulin, Neal M. January 1985 (has links)
The theory of the quadrupole interaction in nuclear magnetic resonance spectroscopy and relaxation measurements is presented in detail, with applications to ²H-NMR studies of order and dynamics in bilayers of deuterated lipids. Investigations of lipid-protein interactions in reconstituted membrane systems and intact biological membranes are reviewed. An experimental program is described which uses a synthetic amphiphilic polypeptide, with known geometry and variable length, to isolate questions about the geometrical interpretation of orientational order in lipid-protein interactions. A report is presented of an investigation of the effects of this polypeptide, Lys₂-Gly-Leu₂₀-Lys₂-Ala-amide, on the mixed bilayer system: Dimyristoylphosphatidylcholine Di-per-deuterio-myristoylphosphatidic Acid. The addition of the peptide was found to have little effect (≤5%) on the first and second moments of the distribution of quadrupole splittings in the liquid crystalline phase. Similarly, the spin-lattice relaxation time constants were affected by ≤10% in the liquid crystalline phase. The time constant for the decay of the quadrupole echo decreased dramatically above the phase transition with the addition of peptide, a phenomenon which is explained in terms of the presence of a new slow motion in the lipid-peptide systems. A simple model of the slow motion induced by the peptide is proposed, in which the lipid molecules undergo a rapid exchange between boundary and bulk sites. An effective correlation time is determined from an average over the rotations on each of these sites. Using this model, estimates are made of the change in the second moment brought about by the onset of the rotations, and. of the number of binding sites on the peptide. These estimates are found to be in agreement with independent measurements of the change in the second moment, and the number of binding sites is within the range predicted by simple considerations of charge balance. The change in the lineshape with the variation of the spacing of the pulses in the quadrupole echo experiment was investigated, and it was determined that the transverse relaxation time constants have a slight orientation dependence. It was also determined that the addition of the peptide has no significant effect on the variation of the lineshape. Some experiments which could answer some of the questions raised by these results are suggested. / Science, Faculty of / Physics and Astronomy, Department of / Graduate
79

Aspects of NMR imaging and in vivo spectroscopy

Talagala, Sardha Lalith January 1986 (has links)
The work described in this thesis deals mainly with aspects related to two- and three-dimensional NMR imaging. A detailed discussion on frequency-selective excitation using amplitude modulated rf pulses in relation to slice selection in NMR imaging has been presented. This includes the analysis and implementation of the method as well as illustrative experimental results. Several radiofrequency probe designs suitable for high field NMR imaging have been experimentally evaluated and their modification and construction are also described. The comparative results obtained indicate the merits and demerits of different designs and provide necessary guidelines for selecting the most suitable design depending on the application. Practical aspects of two- and three-dimensional imaging have been discussed and NMR images of several intact systems have been presented. Experimental methods which enable slice selection in the presence of chemically shifted species and two-dimensional chemical shift resolved imaging have "been described and illustrated using phantoms. The use of three-dimensional chemical shift resolved imaging as a potential method to map the pH and temperature distribution within an object has also been demonstrated. A preliminary investigation of the application of ³¹P NMR spectroscopy to study the biochemical transformations of the rat kidney during periods of ischemia and reperfusion has been presented. / Science, Faculty of / Chemistry, Department of / Graduate
80

Heme Proton Resonance Assignments and Kinetics Study in High-spin and Mixed-spin Metmyoglobin Complexes by Chemical Exchange NMR Spectroscopy

Luo, Ying 15 February 1996 (has links)
NMR studies of paramagnetic hemoproteins have improved significantly our understanding of the structure-function relationship ofhemoproteins in general. Up to date most of the studies focus on low-spin ferric systems which are characterized by relatively narrow resonance peaks and concomitant better resolution. However, characterizing in detail the NMR spectra of high-spin ferric hemoproteins is important since there are several hemoproteins, such as peroxidases, catalases, oxygenases, and some ferricytochromes that contain high-spin iron (III) in their biologically active forms. Yet assigning resonances from heme peripheral protons and/or heme pocket residues in high-spin myoglobins is a daunting undertaking. Only a sparse number of active site residues are assigned in such instances, even for metaquo-myoglobin. The protons from the heme and heme pocket residues in high-spin complexes experience extremely fast relaxation and very broad linewidths, which impede the 2D methods that detect through-space and through-bond connectivities. It is the intention of this study to develop an effective strategy to gain more resonance assignments for fast-relaxing protons in hemoproteins. We have set out to use a combined strategy, using two-dimensional exchange spectroscopy (2D-EXSY) with two dimensional nuclear Overhauser effect spectroscopy I correlation spectroscopy I total correlation spectroscopy (NOESY/COSY/TOCSY). I demonstrate here that 2D EXSY experiments can be used to obtain assignment correlations for the heme protons of methydroxy-, metthiocyano-, metaquo-, and metimidazole-myoglobin forms. All these assignments are unambiguous and straightforward. Moreover, saturation-transfer experiments allow determination of ligand binding kinetics. Thus, the exchange rates between the metaquo- and metimidazole- or methyl substituted imidazole myoglobin complexes are estimated. The differences between the exchange rates reflect the differences in the hydrophobic and steric interactions between the ligands and the protein moiety. Although I only demonstrate the feasibility of2D EXSY for the myoglobin case, this assignment strategy should to be applicable to other hemoprotein systems.

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