Showing papers in "Journal of Magnetic Resonance in 1988"

TL;DR: A new series of broadband heteronuclear decoupling sequences, called the DIPSI sequences, which give better quality decouplings of protons from carbon-13 than previous sequences like WALTZ-16 when there is scalar coupling among the protons.

TL;DR: In this article, a simple algorithm is presented, which permits recognition of all echos occurring in periodic multipulse sequences, and a RARE experiment based on these principles delivers sufficient signal intensity even with small refocusing flip angles.

TL;DR: In this article, the authors proposed heteronuclear 3D NMR spectroscopy to aid in the simplification of two-dimensional proton spectra of isotopically labeled compounds.

TL;DR: In this article, a variable-rate selective excitation (VRS) procedure was proposed to reduce the RF amplitude for duration at each sample of a spatially selective pulse with only mild smearing of the off resonance slice profile.

TL;DR: In this article, an approach to suppress spurious resonances due to the probe in NMR is presented which utilizes DEPTH (I) pulse sequences to select homogeneous regions of the radiofrequency field.

TL;DR: COM as discussed by the authors is a structure refinement algorithm based on the quantitative calculation of 2D NOE intensities taking into account the effects of network relaxation and spin diffusion, which can be used as constraints in energy minimization of the structure to arrive at an improved structure for recycling into COMATOSE.

TL;DR: In this paper, the effects of diffusion of nuclear spins on the echo amplitudes in a multiple echo sequence are analyzed in a medium containing random distributions of susceptibility variations, and it is shown that the apparent transverse relaxation rate is directly proportional to the variance of the distribution of the magnetic field gradients in a heterogeneous region.

TL;DR: In this paper, the authors describe a phase-modulated HMBC experiment, where two sets of detected signals are modulated in phase by the homonuclear J couplings and modulated by the offset frequency of the 13C nucleus, Qc.

TL;DR: The deuteron two-dimensional exchange experiment for the study of slow molecular motions in polycrystalline and amorphous solids is presented in this paper, where a pair of four-pulse sequences for obtaining pure phase 2D spectra of a spin I = 1 system and phase cycles for minimizing artifacts are derived from spin dynamics calculations.

TL;DR: In this paper, the authors obtained 17 O nuclear magnetic resonance spectra of a variety of 17 O-labeled solids using high-field static and "magic-angle" sample spinning techniques, together with 1 H cross polarization and dipolar decoupling.

TL;DR: A shield circuit includes shielding wires and a shielding wire driving circuit, the shielding wires being provided along a target wire that requires shielding, and the shieldingwire driving circuit driving the shielding wire with a logical value corresponding to a logicalvalue of at least one of inputs to a cell that drives the target wire.

TL;DR: Spin trapping is a technique in which highly reactive free radicals are detected by reaction with a diamagnetic molecule (usually a nitrone or nitroso compound) to form more stable free radicals (spin adducts) that can be observed by conventional electron spin resonance spectroscopy as mentioned in this paper.

TL;DR: In this article, the authors examined the factors that govern the B1 tolerance of these pulses and illustrate that previously used amplitude/frequency modulation functions sin/cos, sech/tanh, or constant/tan are far less than optimum in achieving maximal B1 insensitivity on resonance.

TL;DR: In this paper, a minor variation of the P.E.COSY experiment was used to purge the dispersive character of the diagonal in a regular COSY (P.E., 1 I ) experiment.

TL;DR: In this article, the authors presented the first observation of resonant transfer of electron spin polarization to a nuclear spin system, which is called nuclear spin orientation via electron spin locking (NOVEL) and is similar to the technique of dynamic nuclear polarization (I).

TL;DR: In this article, an optimal selective 180° inversion RF pulse can be used as a selective refocusing RF pulse; this is verified experimentally by a spin-echo pulse sequence.

TL;DR: In this paper, the distribution of chemical shifts in 1 H nuclear magnetic resonance spectra of water-soluble, diamagnetic polypeptides and proteins has been analyzed on the basis of the available data from those polypeptic (proteins) where almost all resonances have been assigned by two-dimensional magnetic resonance methods.

TL;DR: In this article, the quadrupole interaction parameters of half-integer spin nuclei are accessible from the dependence of NMR central transition magnetization on the RF excitation pulse length.

TL;DR: In this paper, it was shown that the Carr-Purcell-Meiboom-Gill (CPMG) sequence is equivalent to a spin-locking sequence in the limit of short interpulse spacing (tcp).

TL;DR: In this paper, it is demonstrated that NMR images may be obtained from solids rotating at the magic angle, and it is suggested that imaging be performed with a combination of MAS and multiple pulse line narrowing.

TL;DR: In this paper, the first data point problem was shown to apply to real and complex NMR spectra, where the real and imaginary components are sampled in a sequential manner, and it was shown that if the detected signal is a decaying sinusoid,

TL;DR: In this article, a modified version of the P.E.COSY experiment is used for measuring couplings to the H2′ and H2″ protons in DNA, which uniquely determine the phase of the pseudorotation of the deoxyribose ring.

TL;DR: In this paper, a method is described for semiquantitative evaluation of Hartmann-Hahn contributions to cross peaks in a spin-locked NOE (ROESY) experiment.