Fortune

About: Fortune is a based out in . It is known for research contribution in the topics: Nuclear magnetic resonance spectroscopy & Signal. The organization has 935 authors who have published 963 publications receiving 16646 citations.

Atomic Resolution Structure of Monomorphic Aβ42 Amyloid Fibrils

Abstract: Amyloid-β (Aβ) is a 39–42 residue protein produced by the cleavage of the amyloid precursor protein (APP), which subsequently aggregates to form cross-β amyloid fibrils that are a hallmark of Alzheimer’s disease (AD). The most prominent forms of Aβ are Aβ1–40 and Aβ1–42, which differ by two amino acids (I and A) at the C-terminus. However, Aβ42 is more neurotoxic and essential to the etiology of AD. Here, we present an atomic resolution structure of a monomorphic form of AβM01–42 amyloid fibrils derived from over 500 13C–13C, 13C–15N distance and backbone angle structural constraints obtained from high field magic angle spinning NMR spectra. The structure (PDB ID: 5KK3) shows that the fibril core consists of a dimer of Aβ42 molecules, each containing four β-strands in a S-shaped amyloid fold, and arranged in a manner that generates two hydrophobic cores that are capped at the end of the chain by a salt bridge. The outer surface of the monomers presents hydrophilic side chains to the solvent. The interface...

Experimental Quantum Error Correction

Abstract: Quantum error correction is required to compensate for the fragility of the state of a quantum computer. We report the first experimental implementations of quantum error correction and confirm the expected state stabilization. A precise analysis of the decay behavior is performed in alanine and a full implementation of the error correction procedure is realized in trichloroethylene. In NMR computing, however, a net improvement in the signal to noise would require very high polarization. The experiment implemented the three-bit code for phase errors using liquid state NMR.

Highly efficient, water-soluble polarizing agents for dynamic nuclear polarization at high frequency.

Abstract: Well polarized: Two new polarizing agents PyPol and AMUPol soluble in glycerol/water mixtures are used for dynamic nuclear polarization (DNP) NMR spectroscopy. The enhancement factors (e) are about 3.5 to 4 times larger than for the established agent TOTAPOL at 263 and 395 GHz. For AMUPol, the temperature dependence of e allows DNP experiments to be performed at temperatures significantly higher than for typical high-field DNP NMR experiments.