A realistic pseudopotential model is introduced to investigate the phonon-induced spin relaxation of conduction electrons in bulk silicon. We find a surprisingly subtle interference of the Elliott and Yafet processes affecting the spin relaxation over a wide temperature range, suppressing the significance of the intravalley spin-flip scattering, previously considered dominant, above roughly 120...

Exchange-transferred nuclear Overhauser enhancement (etNOE) provides a useful method for determining the 3dimensional structure of a ligand bound to a high-molecular-weight complex. Some concern about the accuracy of such structures has arisen because indirect relaxation can occur between the ligand and macromolecule. Such indirect relaxation, or spin diffusion, would lead to errors in interpro...

Background Conventional MRI techniques cannot demonstrate microvascular alterations in mild and moderate Alzheimer’s disease (AD). Thus, the diagnosis of pathology commonly relies on postmortem. The purpose this study was to evaluate structures patients with AD using a 3T clinical system commercially available contrast agent. Method Eleven 11 non-AD controls were included cross-sectional prospe...

The effect of high volume fraction of magnetic nanoparticles (MNP) on Magnetic Resonance Imaging (MRI) transverse relaxation rates (R2 = 1/T2 and R2* = 1/T2*) is investigated using Monte Carlo (MC) simulations. Theoretical models assume that particles occupy a small volume fraction of the sample space. Results presented in this work show that models based on both motional averaged (MAR) and sta...

The relaxation mechanism of an initially straight flexible or stiff polymer chain of length N in a viscous solvent is studied through Brownian dynamics simulations covering a broad range of time scales. After the short-time free diffusion, the chain's longitudinal reduction R2(0)-R2 approximately Nt1/2 at early intermediate times is shown to constitute a universal behavior for any chain stiffne...

We discuss the relaxation of a spin-polarized alkali-metal vapor due to the electric-quadrupole interaction in Sg 1 dimers, and present a model that accurately describes the measured relaxation rates under a wide variety of conditions. We use the model along with experimental results to deduce the quadrupole interaction strength, atom-dimer chemical-exchange reaction rate, and the rate of reori...

The purpose of this study was to establish a method for monitoring the neural differentiation of stem cells using ferritin transgene expression, under the control of a neural-differentiation-inducible promoter, and magnetic resonance imaging (MRI). Human adipose tissue-derived mesenchymal stem cells (hADMSCs) were transduced with a lentivirus containing the human ferritin heavy chain 1 (FTH1) g...

In order to describe correctly the interplay of extrinsic and intrinsic spin-orbit mechanisms to the spin Hall effect, it is necessary to consider different sources of spin relaxation. We take into account the spin relaxation time τDP due to the Dyakonov-Perel mechanism as well as the Elliot-Yafet spin-relaxation time τs due to the spin-orbit scattering from impurities. The total spin Hall cond...