In order to show that for a possible application in medical diagnosis NMR-relaxation experiments at low Larmor frequencies (v0 less than or equal to 20 kHz) are more sensitive than the up to now done high field measurements in the MHz-range, we present dispersion curves (v0 = 50 Hz to 50 MHz) of the proton longitudinal relaxation time T1 and values of the transversal relaxation time T2 for the ...

We demonstrate that activation-induced manganese-enhanced magnetic resonance imaging with quantitative determination of the longitudinal relaxation time (qAIM-MRI) reveals the severity of Parkinson's disease (PD) in mice. We first show that manganese ion-accumulation depends on neuronal activity. A highly active region was then observed by qAIM-MRI in the caudate-putamen in PD-model mice that w...

Thurber and Tycko recently described a 'bleaching effect' that occurs in magnetic resonance when solid samples that are doped with paramagnetic agents are subjected to rotation by magic angle spinning (MAS) in a static magnetic field with a rotation period comparable to the longitudinal relaxation time T1e of the electron spins. The bleaching effect has been investigated by Thurber and Tycko in...

The (13)C spin-lattice relaxation times, T(1)'s, of several amino acids have been measured as a function of pD and concentration. A strong dependence of the carboxyl carbon T(1) was observed for both pD and concentration and is believed to be due to intermolecular associations. For the carboxyl carbon, spin rotation is proposed as the predominant relaxation mechanism, whereas the other carbons ...

Diffuse interstitial or replacement myocardial fibrosis is a common feature of a broad variety of cardiomyopathies. Myocardial fibrosis leads to impaired cardiac diastolic and systolic function and is related to adverse cardiovascular events. Cardiovascular magnetic resonance (CMR) may uniquely characterize the extent of replacement fibrosis and may have prognostic value in various cardiomyopat...

The available theoretical approaches aiming at describing Dynamic Nuclear spin Polarization (DNP) in solutions containing molecules of biomedical interest and paramagnetic centers are not able to model the behaviour observed upon varying the concentration of trityl radicals or the polarization enhancement caused by moderate addition of gadolinium complexes. In this manuscript, we first show exp...

NMR measurements ((119)Sn chemical shift, line width and (13)C relaxation) were made on triphenyltin chloride in two solutions, 2.5 and 0.75 mol% in CDCl(3), at several temperatures. The (13)C spin-lattice relaxation time and NOE data for the phenyl carbons provide the corresponding correlation times for the overall molecular reorientational motion and the internal rotation of the phenyl groups...

The spin dynamics of NMR spin locking of proton magnetization under a frequency-switched Lee-Goldburg (FSLG) pulse sequence is investigated for a better understanding of the line-narrowing mechanism in PISEMA experiments. For the sample of oriented 15N(1,3,5,7)-labeled gramicidin A in hydrated DMPC bilayers, it is found that the spin-lattice relaxation time T(1rho)(H) in the tilted rotating fra...

The mobility of pseudomonic acid A in dimethyl sulfoxide-d6 solution has been determined from 13C spin-lattice relaxation time measurements at two field strengths. The central tetrahydropyran ring reorientates isotropically with a rotational correlation time of approximately 280 picoseconds/ radian . Both side-chains exhibit marked segmental motion with correlation times decreasing to only appr...

The S = 1/2 Heisenberg antiferromagnet in the ladder geometry is studied as a model for the spin degrees of freedom of SrCu2O3. The susceptibility and the spin echo decay rate are calculated using a quantum Monte Carlo technique, and the spin-lattice relaxation rate is obtained by maximum entropy analytic continuation of imaginary time correlation functions. All calculated quantities are in rea...