“Malaria” is a life-threatening blood disease in tropical regions that spreads by the bite of the Anopheles mosquito. Antimalarial medications are designed to cure or prevent this infection, and prosperous achievements in this area mostly depend on the knowing the drug-receptor interactions and active sites of medicine. This improvement can be achieved through understanding the electronic struc...

In solid-state NMR of quadrupolar nuclei with half-integer spin I, a variety of fast amplitude-modulated (FAM) pulse trains have been used to enhance the intensity of the central-transition signal, by transferring spin population from the satellite transitions. Here, we describe the results of extensive numerical calculations using the Simpson program package to evaluate and compare the signal ...

A sensitivity enhancement method based on selective adiabatic inversion of a satellite transition has been employed in a (pi/2)CT-(pi)ST1-(pi/2)CT spectral editing sequence to both enhance and resolve multisite NMR spectra of quadrupolar nuclei. In addition to a total enhancement of 2.5 times for spin 3/2 nuclei, enhancements up to 2.0 times is reported for the edited sites in a mixture of rubi...

The dependence of the (Rotor Assisted Population Transfer) RAPT enhancement on offset frequency for nuclei experiencing different quadrupolar couplings has been exploited to design two new spectral editing schemes, pi/2-RAPT and RAPT-pi-RAPT, for the selective excitation or suppression, respectively, of nuclei with large quadrupolar couplings. Both approaches are demonstrated on the 87 Rb spect...

A balanced probe circuit is used to generate high B(1) magnetic field for sensitivity enhancement of multiple-quantum magic-angle spinning (MQMAS) experiment applied to low-gamma quadrupolar nuclei. Electrical balancing of the sample coil can cut the peak voltage by a half, therefore improving the power handling when generating a two-fold higher B(1) field. Experimental results, illustrated her...

We report the application of rotor-assisted population transfer (RAPT) to measure the quadrupolar coupling constant (C(q)) for spin 5/2 nuclei. Results from numerical simulations are presented on the magnitude of enhancement factor as a function of frequency offsets, i.e. the RAPT profile. Experimental O17 RAPT profile is traced for the amino acid L-leucine. In addition, results from MQ-MAS exp...

Strain-induced gradients of local electric fields in semiconductor quantum dots can couple to the quadrupole moments of nuclear spins. We develop a theory describing the influence of this quadrupolar coupling on the spin correlators of electron and hole "central" spins localized in such dots. We show that when the quadrupolar coupling strength is comparable to or larger than the hyperfine coupl...

Molecular-scale dynamics on the nanosecond timescale or faster can have a measureable influence on isotropic NMR frequencies of quadrupolar nuclei. Although previously studied in solution, where it is usually referred to as the "dynamic shift", this effect is less well known in solids. Here we demonstrate that multiple-quantum NMR measurements of isotropic quadrupolar shifts are a simple way to...

Light excitation of a semiconductor, known to dynamically-polarize the nuclear spins by hyperfine contact interaction with the photoelectrons, also generates an intrinsic nuclear depolarization mechanism. This novel relaxation process arises from the modulation of the nuclear quadrupolar Hamiltonian by photoelectron trapping and recombination at nearby localized states. For nuclei near shallow ...

Tyrosinase is a multifunctional copper-containing enzyme. It can catalyze two distinct reactions of melanin synthesis and benzaldehyde derivatives, which are potential tyrosinase inhibitors.  To find the relationships between charge distributions of benzaldehyde and their pharmaceutical behavior, the present study aimed at investigating nuclear quadrupole coupling constants of quadrupolare nucl...