The neutral host cucurbit[7]uril forms very stable complexes with a series of cationic cholines (R(3)NCH(2)CH(2)OR'(+)) and their phosphonium analogues (R(3)PCH(2)CH(2)OR'(+)) (R(3) = Me(3), Et(3), or Me(2)Bz, or R(3)N = quinuclidinium, and R' = H, COCH(3), CO(CH(2))(2)CH(3), or PO(3)H), and (+/-)-carnitine, in aqueous solution. The complexation behaviour has been investigated using (1)H and (3...

We survey the principles for the design of multidimensional vibrational spectroscopies that draw upon the analogy with liquid or solid state NMR and EPR spectroscopy. The much faster time-scales and the different energy regime in laser spectroscopy provide additional possibilities that lack magnetic spectroscopy counterparts. We also discuss the notion of through-bond vs through-space couplings...

in this research, the characteristics of cmp dioxane lignin (hardwood origin) and soda bagasse lignin (ethanol soluble fraction) and dioxane lignin of bagasse were studied using gel permeation chromatography, gas chromatography-mass spectrometry and 13c nmr spectroscopy and dfrc degradation procedure. the results indicated that the main structural units in lignins are phenyl propane skeletons b...

Nuclear magnetic resonance (NMR) spectroscopy is a powerful technique for structural studies of chemical compounds and biomolecules such as DNA and proteins. Since the NMR signal sensitively reflects the chemical environment and the dynamics of a nuclear spin, NMR experiments provide a wealth of structural and dynamic information about the molecule of interest at atomic resolution. In general, ...

Nuclear magnetic resonance spectroscopy provides non-invasive and non-destructive access to the chemistry of human tissue in situ. Two studies presented in this issue of the Journal [1, 2] apply this new technique on skeletal muscle metabolism in patients with chronic lung disease. In the 1940s, E. Purcell and F. Bloch discovered that electromagnetic radio-frequency energy could be used to inte...

the thermo-oxidative degradation of two viscous liquid resins of 1,2- poly-butadiene  (1,2-pbd) and 1,4- polybutadiene  (1,4-pbd) have been studied by differential scanning calorimetry (dsc) and thermogravimetry analy-sis  (tga). to  study  further,  the  effect of flm  thickness on oxidation kinetics was periodically studied by tracing the weight of the samples to make comparison with dsc resu...

Solution NMR spectroscopy represents a powerful tool for examining the structure and function of biological macromolecules. The advent of multidimensional (2D-4D) NMR, together with the widespread use of uniform isotopic labeling of proteins and RNA with the NMR-active isotopes, 15N and 13C, opened the door to detailed analyses of macromolecular structure, dynamics, and interactions of smaller ...

The higher order structure (HOS) of biotherapeutics is a critical quality attribute that can be evaluated by nuclear magnetic resonance (NMR) spectroscopy at atomic resolution. NMR spectral mapping of HOS can be used to establish HOS consistency of a biologic across manufacturing changes or to compare a biosimilar to an innovator reference product. A previous inter-laboratory study performed us...

A new approach for accurate quantitative determination by fluorine nuclear magnetic resonance ( 19 F NMR) spectroscopy is presented and discussed. 19 F NMR spectroscopy has similar properties to 1 H NMR spectroscopy except for the wide chemical shift dispersion, which is the main difference between the two techniques. The off-resonance effect, which is caused by the chemical shift difference be...

Bipolar disorder (BD) is a debilitating mental disorder that cannot be diagnosed by objective laboratory-based modalities. Our previous studies have independently used nuclear magnetic resonance (NMR)-based and gas chromatography-mass spectrometry (GC-MS)-based metabonomic methods to characterize the urinary metabolic profiles of BD subjects and healthy controls (HC). However, the combined appl...