The present paper considers the possibility to obtain a magnetic ordering of the proton spins in molecular crystals of fluorene using dynamic nuclear polarization (DNP) followed by adibatic demagnetization in the rotating frame (ADRF). It is found that such an ordering is most easily reached for T < 0 and 80 II c-axis. Then a polarization of only 26% needs to be reached by DNP in order to obtai...

This article discusses the basic concepts of Magnetic Resonance Imaging (MRI) with the intention to introduce the subject to uninitiated. The MRI technique is a powerful noninvasive probe of the body's internal anatomy. In MRI, the images are produced not by X-rays, but through the use of non-ionizing radiowaves that stimulate transitions between spin states of nuclei in a magnetic field when p...

A H–C frequency-selective REDOR (FS-REDOR) experiment is developed for measuring intramolecular H–C distances in uniformly C, N-labeled molecules. Theory and simulations show that the experiment removes the interfering homonuclear H–H, C–C and heteronuclear H–N, C–N dipolar interactions while retaining the desired heteronuclear H–C dipolar interaction. Our results indicate that this technique, ...

A detailed understanding of the function of a biological macromolecule requires knowledge of its three-dimensional structure. Most atomic-resolution structures of biological macromolecules have been solved either by X-ray diffraction in single crystals or by nuclear magnetic resonance (NMR) in solution. This review surveys the method of NMR structure determination. First, a brief introduction t...

Natural abundance 13C nuclear magnetic resonance spectroscopy was used to detect signals from glycogen in the human gastrocnemius muscle. The reproducibility of the measurement was demonstrated, and the ability to detect dynamic changes was confirmed by measuring a decrease in muscle glycogen levels after exercise and its subsequent repletion. Single frequency gated 1H decoupling was used to ob...

In high-field nuclear magnetic resonance (NMR) spectroscopy, the sensitivity of the xenon chemical shift to its environment1 has been exploited to study porosity and surface interactions in materials2, as well as to probe xenon interactions with molecules3 and proteins4 in solution. In recent years, polarization enhancement through optical pumping5 techniques has further advanced the utility of...

As methods for analysis of biomolecular structure and dynamics using nuclear magnetic resonance spectroscopy (NMR) continue to advance, the resulting 3D structures, chemical shifts, and other NMR data are broadly impacting biology, chemistry, and medicine. Structure model assessment is a critical area of NMR methods development, and is an essential component of the process of making these struc...

We demonstrate one-dimensional nuclear magnetic resonance imaging of the semiconductor GaAs with 170 nanometer slice separation and resolve two regions of reduced nuclear spin polarization density separated by only 500 nanometers. This is achieved by force detection of the magnetic resonance, Magnetic Resonance Force Microscopy (MRFM), in combination with optical pumping to increase the nuclear...

In this article, we present an alternative expansion scheme called Floquet-Magnus expansion (FME) used to solve a time-dependent linear differential equation which is a central problem in quantum physics in general and solid-state nuclear magnetic resonance (NMR) in particular. The commonly used methods to treat theoretical problems in solid-state NMR are the average Hamiltonian theory (AHT) an...

The effect of the magnetic field on the electrostatic potential of electrons inside and in close vicinity outside the quark surface of the star is studied. Depending on the value of the crust potential and the electron chemical potential at the base of the nuclear crust, we find that the strong surface magnetic field, 1.0 × 1014 ≤ H ≤ 3.0 × 1016 Gauss leads to a considerable reduction of the el...