The behavior of surfactants in solution has been and still is of scientific, technological, and industrial interest. The micelle forming compounds sodium N( octyloxycarbonyl)sarcosinate (NaOcSarc), and sodium N-(decyloxycarbonyl)sarcosinate (NaDecSarc) show in aqueous solution two lH NMR N-methyl peaks arising from a possible cis- or trans-conformation. The relative population of the N-methyl peaks depends mostly on the concentration of surfactant indicating micelle formation. Upon heating the two peaks start to coalesce and finally appear as one single peak . The temperature range in which this phenomenon occurs is from 25°C to 65°C. The primary interest of this study was to determine the activation parameters of rotation about the carbonyl-nitrogen (C-N) bond. Dynamic nuclear magnetic resonance spectroscopy was employed to approach this problem. A complete bandshape analysis was performed in order to calculate the free energy (G++), enthalpy (H++), and entropy (S++) of activation. The effect of a different counter ion (Li+) and sodium chloride salt addition were tested for possible changes of the activation parameters. Studies in nonaqeous solvents were conducted with the free acid form of the mentioned carbarnates. Dimethylsulfoxide and chloroform were chosen as organic solvents for these particular experiments. The critical micellar concentrations of all surfactants were determined, and the assignment of the individual N-methyl peaks to the correspondend conformation could be unambiguously shown by a two dimensional NMR experiment. The cmc's show strong salt dependence. The effect of a lithium as an alternative counter ion has a less drastic effect. Micellization seems not to occur in the free acid cases. Interestingly, the surfactants show stronger salt dependence than micellization dependence upon the activation parameters, indicating that solvent exposure occurs at the C-N partial double bond and considerable deformation of the ideal spherical shape.

Six novel platinum(II) intercalators of the form [Pt(AL)(IL)]Cl2, where AL = ethylenediamine (en), 1R,2R-diaminocyclohexane (R,R-dach), or 1S,2S-diaminocyclohexane (S,S-dach) and IL = 4,7-dihydroxy-1,10-phenanthroline (4,7-dhp) or 4,7-dicarboxy-1,10-phenanthroline (4,7-dcp), were synthesised. All complexes were prepared by the addition of the intercalating ligand followed by the addition of the diamine ancillary ligand. The complexes with 4,7-dhp were soluble in DMSO and were characterised by 1H, 13C, and 195Pt NMR, elemental analysis, UV-vis, ESI-MS, and CD. The complexes with 4,7-dcp were only soluble in a highly acidic solution and, therefore, were characterised only by 1H NMR and elemental analysis. The cytotoxicity of the 4,7-dhp complexes was tested in the L1210 murine leukaemia cell line. [Pt(S,S-dach)(4,7-dhp)]Cl2 showed an IC50 value of > 80 μM. The antitumour and antibacterial activities of all six complexes were tested in vitro using the Kirby-Bauer disc diffusion method with Staphylococcus aureus and Agrobacterium tumefaciens. The 4,7-dhp complexes showed no activity to these bacteria strains. The activities of the 4,7-dcp complexes were not able to be tested due to their solubility only in acidic solutions, which itself inhibits cell growth. The diffusion coefficients of the Pt(II) intercalators of the form [Pt(AL)(IL)]Cl2, where AL = en, R,R-dach, or S,S-dach and IL = phen, 4-mp, 4,7-dmp, 4,7-dhp, 4,7-dcp or 3,4,7,8-tmp and various starting materials used during the synthesis of these complexes were measured using pulsed gradient spin-echo (PGSE) NMR. The diffusion coefficients of both 4,7-dcp and [Pt(4,7-dcp)Cl2] were observed to be lower than other compounds with similar molecular weights indicating dimerisation of the compounds. The binding studies of the systems, [Pt(en)(phen)]Cl2 to (i) BSA, (ii) delipidated BSA, and (iii) d(GTCGAC)2 were studied using a simple two-site binding model with diffusion NMR. The binding of [Pt(en)(phen)]Cl2 – BSA was well described by the model giving the values Kd = 0.0021 ± 0.0002 M and n = 5.85 ± 0.31. On the contrary, the binding of [Pt(en)(phen)]Cl2 – delipidated BSA showed a poor fit to the model. From the poor fit of the data, it was speculated that the transverse relaxation of BSA largely affected the system. The binding of [Pt(en)(phen)]Cl2 – d(GTCGAC)2 showed results where the diffusion coefficient decreases as the concentration of the drug increases but an opposite effect was observed from the point where the drug reached equimolar concentrations to d(GTCGAC)2. It was speculated that the drug undergoes allosteric binding to the biomolecule or that a conformational change occurred as the drug concentration increases in the system. A further study of [Pt(en)(phen)]Cl2 and K2PtCl4 using 195Pt diffusion NMR was conducted giving a diffusion coefficient of 3.08 ± 0.04 × 10-10 m2 s-1 for K2PtCl4. The diffusion coefficient of [Pt(en)(phen)]Cl2, however, were unobtainable due to the short transverse relaxation of the Pt complex. / Master of Science (M.Sc.) (Hons)

Molecular diffusion is an inherent feature of all fluid systems. The processes and interactions that characterize these systems are in some way dependent upon the mobility of the component molecules. Pulsed field-gradient spin-echo nuclear magnetic resonance (PGSE NMR) is a powerful tool for the study of molecular diffusion; for heterogeneous systems, such as those typically found in biology, this technique is unsurpassed in the diversity of systems that yield to its probing. The aim of the work presented in this thesis was to use an integrated NMR-based approach, in conjunction with computer modeling, for the study of molecular diffusion in compartmentalized and multicomponent biological systems. Erythrocyte suspensions provided an ideal experimental system for the study of compartmentalized diffusion in cells. Water exchanges rapidly between the intra- and extracellular regions and, as the major constituent of the cell, provides a strong and predominant proton NMR signal. In addition, the cells are known to align in the strong static magnetic field of the spectrometer. As a consequence of these two properties, the signal intensity from a suitably designed series of PGSE NMR experiments exhibits a series of maxima and minima when graphed as a function of the magnitude of the spatial wave number vector q. The apparently periodic phenomenon is mathematically analogous to optical diffraction and interference and is referred to here as diffusion-coherence. It is the characterization of this phenomenon, with the aid of computer-based models, which was the focus of a major section of the work described herein. Two quite distinct molecular systems formed the basis of the work in which I investigated diffusion in multicomponent systems. Both systems involved molecules that undergo self-association such that at equilibrium a population distribution of different oligomeric species is present. The first of these was tropoelastin, the monomeric subunit of elastin, which under certain conditions aggregates to form a coacervate. The second system was N-methylacetamide (NMA) which also undergoes extensive self-association. NMA oligomers have previously been studied as peptide analogues due to the presence in the monomer of a peptide linkage. In this work the aim was to use PGSE NMR diffusion measurements, in a manner that is in many ways analogous to analytical ultracentrifugation, to obtain estimates of hydrodynamic and thermodynamic parameters. Computer modeling was also used extensively in this section of work for the interpretation of the experimental data.

Recent developments in NMR hardware have extended the reach of natural products chemists to structure elucidation of compounds isolated on a nanomolar scale. In parallel with advances in hardware new NMR techniques for structure elucidation have evolved, e.g. quantitative NOEs, residual dipolar couplings (RDCs)and diffusion-ordered spectroscopy (DOSY). The application of recent NMR techniques was utilized in the screening and structural assignment of natural products isolated from a 2004 collection of South African tunicates. Assignment of the planar structures of mandelalides A-D from a new Lissoclinum sp. was feasible only after data acquisition on a 700 MHz magnet equipped with 5 mm ����C cryogenic probe. While relative configuration of the polyketide mandelalides was established after extensive J-coupling and NOE analysis, quantitative ROESY and RDC measurements were also explored before the absolute configuration was accomplished by chemical degradation and comparison with standards. The application of DOSY, a greatly under-appreciated technique in natural products research, led to the identification of new rubrolide analogues, compounds with moderate antibacterial properties from the new species Synoicum globosum. Finally, relative and absolute configuration of new and known unstable amino alcohols from two Pseudodistoma species was based on J-coupling analysis and application of the Mosher method. / Graduation date: 2013

Herman J.C. Berendsen. / "July 2, 1962"--Cover. "Reprinted from the Journal of chemical physics, vol. 36, no. 12, 3297-3305, June 15, 1962." / Bibliography: p. 48. / Army Signal Corps Contract DA36-039 sc-78108. Dept. of the Army Task 3-99-20-001 and Project 3-99-00-000.

Nelson L. Alpert. / "July 31, 1948." "Condensation of a thesis." / Includes bibliographical references. / Army Signal Corps No. W-36-039 sc-32037.

In this paper we examine the reconstruction of functions of any dimension from hyperplanar projections. This is a generalization of a problem that has generated much interest recently, especially in the field of medical imaging. Computed Axial Tomography (CAT) and Nuclear Magnetic Resonance (NMR) are two medical techniques that fall in this framework. CAT scans measure the hydrogen density along planes through the body. Here we will examine reconstruction methods that involve backprojecting the projection data and summing this over the entire region of interest. There are two methods for doing this. One method is to filter the projection data first, and then backproject this filtered data and sum over all projection directions. The other method is to backproject and sum the projection data first, and then filter. The two methods are mathematically equivalent, producing very similar equations. We will derive the reconstruction formulas for both methods for any number of dimensions. We will examine the cases of two and three dimensions, since these are the only ones encountered in practice. The equations are very different for these cases. In general, the equations are very different for even and odd dimensionality. We will discuss why this is so, and show that the equations for even and odd dimensionality are related by the Hilbert Transform.

Thesis (Ph. D.)--University of Washington, 2006. / Vita. Includes bibliographical references (p. 119-136).

Ball State University LibrariesLibrary services and resources for knowledge buildingMasters ThesesThere is no abstract available for this thesis.

A miniaturized super-regenerative nuclear quadrupole resonance spectrometer was fabricated in this project. The spectrometer was constructed using thin-film chromium resistors, gold-nickel conductors, and field effect transistors. The unit operated at room temperature and at 77º K between the frequencies of 24.860 and 44.300 MHs.The spectrometer was fabricated on a ceramic substrate which was 5.08 x 5.08cm. The films consisted of vacuum deposited chromium, electroless plated nickel, and electroplated gold. The resistor-conductor pattern was photo-etched from the films and the remaining components attached to the films to form the circuit.The spectrometer was encased in a stainless steel belljar with the sample coil extending from the bottom and the signal and power leads extending from the top of the belljar. The unit was immersed in liquid nitrogen and the characteristics monitored as the temperature dropped.The spectrometer operated in the liquid nitrogen, but failed to yield a signal for a paradichlorobenzene sample. The spectrometer exhibited poor frequency selectivity and a frequency change of 2MHz (6%) in going from room temperature to liquid nitrogen (77º K).Ball State UniversityMuncie, IN 47306