Nuclear magnetic resonance spectroscopy disorder

Soares JC, Krishnan KR, Keshavan MS. Nuclear magnetic resonance spectroscopy new insights into the pathophysiology of mood disorders. Depression 1996 4 14-30. 

However, other perspectives suggest that there are likely to be as yet unidentified protein folds. As of 2004, the Pfam database (version 10.0) contained 6190 domains only about a third were associated with a protein of known structure. Some of these may be cases in which highly divergent or completely unrelated sequences adopt an already discovered fold. Some may not be amenable to structural characterization, either because they are too large for characterization by nuclear magnetic resonance spectroscopy (NMR), or contain disordered regions that interfere with crystallization. However, there may indeed be unidentified protein domain structures remaining to be discovered. 

Cavitands. p. 219 Clathrate Hydrates, p. 274 Disorder and Diffuse Scattering, p. 457 Hydrogen Bonding, p. 658 Hydrophobic Effects, p. 673 Isostructurality of Inclusion Compounds, p. 767 Neutron Diffraction, p. 959 Soft and Smart Materials, p. 1302 Solid-State Nuclear Magnetic Resonance Spectroscopy, p. 1307... 

R41 N. W. Lutz and P. J. Cozzone, Metabolic Profiling in Multiple Sclerosis and Other Disorders by Quantitative Analysis of Cerebrospinal Fluid Using Nuclear Magnetic Resonance Spectroscopy , Curr. Pharm. Biotechnol., 2011, 12, 1016. 

R209 F. A. Mulder, M. Lindqvist and R. M. Scheek, Nuclear Magnetic Resonance Spectroscopy Applied to (Intrinsically) Disordered Proteins , in Instrumental Analysis of Intrinsically Disordered Proteins Assessing Structure and Conformation, eds. V. Uversky and S. Longhi, John WUey Sons, Inc., Hoboken, N. J., 2010, p. 61. 

R472 R. Schneider, J.-r. Huang, M. Yao, G. Communie, V. Ozenne, L. Mollica, L. Salmon, J. M. Ringkjobing and M. Blackledge, Towards a Robust Description of Intrinsic Protein Disorder Using Nuclear Magnetic Resonance Spectroscopy , Mol. BioSyst., [online computer file], 2012, 8, 58. 

R. A. lies, Nuclear Magnetic Resonance Spectroscopy and Genetic Disorders , Curr. Med. Chem., 2008, 15, 15. 

To obtain statistically significant comparisons of ordered and disordered sequences, much larger datasets were needed. To this end, disordered regions of proteins or wholly disordered proteins were identified by literature searches to find examples with structural characterizations that employed one or more of the following methods (1) X-ray crystallography, where absence of coordinates indicates a region of disorder (2) nuclear magnetic resonance (NMR), where several different features of the NMR spectra have been used to identify disorder and (3) circular dichroism (CD) spectroscopy, where whole-protein disorder is identified by a random coil-type CD spectrum. 

In earlier literature reports, x-ray data of a-based ceramics, the /3-like phase observed in certain silica minerals was explained by a structural model based on disordered Q -tridymite. However, others have suggested that the structure of the stabilized jS-cristobalite-like ceramics is closer to that of a-cristobalite than that of Q -tridymite, based on the 29Si nuclear magnetic resonance (NMR) chemical shifts (Perrota et al 1989). Therefore, in the absence of ED data it is impossible to determine the microstructure of the stabilized jS-cristobalite-like phase. ED and HRTEM have provided details of the ceramic microstructure and NMR has provided information about the environments of silicon atoms in the structure. Infrared spectroscopy views the structure on a molecular level. 

Another contribution to variations of intrinsic activity is the different number of defects and amount of disorder in the metallic Cu phase. This disorder can manifest itself in the form of lattice strain detectable, for example, by line profile analysis of X-ray diffraction (XRD) peaks [73], 63Cu nuclear magnetic resonance lines [74], or as an increased disorder parameter (Debye-Waller factor) derived from extended X-ray absorption fine structure spectroscopy [75], Strained copper has been shown theoretically [76] and experimentally [77] to have different adsorptive properties compared to unstrained surfaces. Strain (i.e. local variation in the lattice parameter) is known to shift the center of the d-band and alter the interactions of metal surface and absorbate [78]. The origin of strain and defects in Cu/ZnO is probably related to the crystallization of kinetically trapped nonideal Cu in close interfacial contact to the oxide during catalyst activation at mild conditions. A correlation of the concentration of planar defects in the Cu particles with the catalytic activity in methanol synthesis was observed in a series of industrial Cu/Zn0/Al203 catalysts by Kasatkin et al. [57]. Planar defects like stacking faults and twin boundaries can also be observed by HRTEM and are marked with arrows in Figure 5.3.8C [58],... 

From its very beginning nuclear magnetic resonance (NMR) was used to unravel dynamic processes in amorphous matter, where the high selectivity of this technique was exploited. Recent progress has largely benefited from the development of multidimensional NMR spectroscopy, significantly extending the traditional techniques such as spin-lattice relaxation and line-shape analyses. Modern NMR techniques helped a lot to understand the molecular dynamics in disordered systems such as the a-process. 

Solid-state nuclear magnetic resonance (NMR) has been extensively used to assess structural properties, electronic parameters and diffusion behavior of the hydride phases of numerous metals and alloys using mostly transient NMR techniques or low-resolution spectroscopy [3]. The NMR relaxation times are extremely useful to assess various diffusion processes over very wide ranges of hydrogen mobility in crystalline and amorphous phases [3]. In addition, several borohydrides [4-6] and alanates [7-11] have also been characterized by these conventional solid-state NMR methods over the years where most attention was on rotation dynamics of the BHT, A1H4, and AlHe anions detection of order-disorder phase transitions or thermal decomposition. There has been little indication of fast long-range diffusion behavior in any complex hydride studied by NMR to date [4-11]. 

Proton magnetic resonance spectroscopy and C nuclear magnetic resonance (NMR) spectroscopy have been reported to study the nature of water in hiunan SC (Foreman, 1976 Yamamura and Tezuka, 1989 Jokura et al., 1995). The H-NMR data are useful to study dynamic structural disorder of the intercellular lamellar Upid structure in the SC (Bezema etal., 1996). For further information on the use of NMR for investigating SC stmcture, refer to the review by Abraham et al. (1997). 

Solid-state nuclear magnetic resonance (ssNMR) spectroscopy has emerged over the years as a powerful analytical method in solid-state chemistry, especially with the advancements in techniques that allow the acquisition of high-resolution spectra [47]. In the broadest sense, ssNMR is mostly applied in characterization of crystalline materials as a means to support PXRD structural analyses by providing information on the number of molecules in the asymmetric unit or the symmetry of the occupied positions within the unit cell. Another major field of application is the structural characterization of amorphous and disordered solids where standard X-ray diffraction-based techniques fail to give detailed structural information. When discussing ssNMR in the context of API polymorphism and synthesis of co-crystals,... 

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