The relaxation of (1)H nuclei due to their interaction with quadrupolar (14)N nuclei in gel structures is measured using fast field-cycling NMR. This phenomenon called quadrupolar dips has been reported in different (1)H-(14)N bond-rich species. In this study, we have studied quadrupolar dips in fibrin, an insoluble protein that is the core matrix of thrombi. Fibrin was formed by the addition o...

Solid-state NMR technique for measuring distances between hetero-nuclei in static powder samples is described. It is based on a two-dimensional single-echo scheme enhanced with adiabatic cross-polarization. As an example, the results for intra-molecular distances in αcrystalline form of glycine are presented. The measured NMR distances C(2) – N and C(1) – N are 1.496 ± 0.002 Å and 2.50 ± 0.02 Å...

validated in a rigorously controlled study and probably the only solution for any relevant NMR based EBC data. In theory, this new control could provide an unambiguous picture of breath metabolism. 3) Subtracting the air background from the breath signal (alveolar gradient). This method is currently applied in MS breath analysis by measuring the metabolic concentration in volatiles (also in EBC...

Residual heteronuclear dipolar couplings obtained from partially oriented protein samples can provide unique NMR constraints for protein structure determination. However, partial orientation of protein samples also causes severe 1H line broadening resulting from residual 1H-1H dipolar couplings. In this communication we show that band-selective 1H homonuclear decoupling during data acquisition ...

We demonstrate nuclear magnetic resonance (NMR) imaging of the flow and diffusion of laser-polarized xenon (129Xe) gas undergoing convection above evaporating laser-polarized liquid xenon. The large xenon NMR signal provided by the laser-polarization technique allows more rapid imaging than one can achieve with thermally polarized gas-liquid systems, permitting shorter time-scale events such as...

Hyperpolarization of stable isotope-labeled substrates and subsequent NMR measurement of the metabolic reactions allow for direct tracking of cellular reactions in vitro and in vivo. Here, we report the hyperpolarization of (13)C6-glucose-d7 and evaluate its use as probes to observe glucose flux in cells. We measured the lifetime of the polarized signal governed by the spin-lattice relaxation t...

Magnetic field distribution measurement and imaging of thin layers using magnetic resonance techniques on biological samples have been performed. The resultant image represents the magnetic susceptibility distribution in the sample. An NMR imaging method susceptible to the homogeneity of magnetic field Gradient Echo was used. Since the investigated physical or biological samples did not generat...

An in situ approach involving a simple mix and shake method for testing the enantiopurity of primary, secondary and tertiary chiral amines and their derivatives, chiral amino alcohols, by (1)H-NMR spectroscopy is developed. The protocol involves the in situ formation of chiral ammonium borate salt from a mixture of C2 symmetric chiral BINOL, trialkoxyborane and chiral amines. The proposed conce...

Pulsed field-gradient NMR experiments can be used to measure the diffusion constants of nucleic acids. The diffusion constants measured in this way for double-helical DNAs of defined length agree well both with theory and with measurements done using other techniques. When applied to RNAs, this experiment easily distinguishes duplex RNAs from RNA hairpins and thus it can solve one of the perenn...