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...

NMR spectroscopy is a powerful technique for determining structural and functional features of biomolecules in physiological solution as well as for observing their intermolecular interactions in real-time. However, complex steps associated with its practice have made the approach daunting for non-specialists. We introduce an NMR platform that makes biomolecular NMR spectroscopy much more acces...

We investigated temperature distribution in a solid state nuclear magnetic resonance (NMR) sample rotor under magic angle spinning (MAS) experiments by analyzing the (207)Pb chemical shift of solid lead nitrate (Pb(NO3)2). The analysis corrected a mismatch of the temperature dependence of (1)H spin-lattice relaxation time (T1(H)) obtained from different sample positions in the rotor. We prepare...

Recent developments in experimental and computational aspects of NMR spectroscopy have had a significant impact on the accuracy and speed of macromolecular structure determination in solution, particularly with regard to systems of high complexity (such as protein complexes). These include experiments designed to provide long-range orientational and translational restraints, improvements in int...

Determination of precise and accurate protein structures by NMR generally requires weeks or even months to acquire and interpret all the necessary NMR data. However, even medium-accuracy fold information can often provide key clues about protein evolution and biochemical function(s). In this article we describe a largely automatic strategy for rapid determination of medium-accuracy protein back...

1H NMR and static susceptibility measurements have been performed in an organic Mott insulator with a nearly isotropic triangular lattice, kappa-(BEDT-TTF)2Cu2(CN)(3), which is a model system of frustrated quantum spins. The static susceptibility is described by the spin S=1/2 antiferromagnetic triangular-lattice Heisenberg model with the exchange constant J approximately 250 K. Regardless of t...

A strategy for simplified and complete resonance assignment of insoluble and noncrystalline proteins by solid-state NMR (ssNMR) spectroscopy is presented. Proteins produced with [1-(13)C]- or [2-(13)C]glucose are very sparsely labeled, and the resulting 2D ssNMR spectra exhibit smaller line widths (by a factor of ∼2 relative to uniformly labeled proteins) and contain a reduced number of cross-p...

Stochastic resonance (SR) is a phenomenon wherein the response of a nonlin-ear system to a weak periodic input signal is optimized by the presence of a particular level of noise. Here we present a new method and theory for characterizing SR-type behavior in excitable systems with aperiodic inputs. These novel developments demonstrate that noise can serve to enhance the response of a nonlinear s...