Protein NMR Resonance Assignment without Spectral Analysis: 5D SOlid‐State Automated Projection SpectroscopY (SO‐APSY)

Narrow proton signals, high sensitivity, and efficient coherence transfers provided by fast magic‐angle spinning at high magnetic fields make automated projection spectroscopy feasible for the solid‐state NMR analysis of proteins. We present the first ultrahigh dimensional implementation of this approach, where 5D peak lists are reconstructed from a number of 2D projections for protein samples of different molecular sizes and aggregation states, which show limited dispersion of chemical shifts or inhomogeneous broadenings. The resulting datasets are particularly suitable to automated analysis and yield rapid and unbiased assignments of backbone resonances.     

Faraday rotation in single crystal erbium iron garnet

Measurements of the Faraday rotation of ErIG, Er₃Fe₅O₁₂, have been performed in the 4.2–300 K temperature range in magnetic field up to 20 kOe applied along the [111] direction and at 1.15 μm wavelength. The results are analysed under the assumption that the contribution of the Fe³⁺ ions to the total Faraday rotation is the same as that of YIG, Y₃Fe₅O₁₂. The temperature and field dependences of the contribution of the Er³⁺ ions are deduced. Both magnetic and electric dipole contributions of the Er³⁺ ions are calculated; the electric dipole coefficient C_e is found to present a linear temperature dependence between 30–300 K. The temperature dependence of the Faraday rotation susceptibility differs strongly from that of the magnetic susceptibility.     

The decay modes of proton drip-line nuclei with A between 42 and 47

Neutron-deficient isotopes with Z=21 to 26 have been produced as projectile-like fragments of an intense⁵⁸Ni GANIL beam of 69 MeV/nucleon. The nuclei selected by the upgraded LISE3 spectrometer were identified and implanted in a silicon detector telescope. The⁴³Cr,⁴⁷Fe and⁴⁶Fe isotopes were identified for the first time whereas⁴⁵Fe,⁴⁵Mn,⁴⁴Mn and⁴²V were not observed, indicating probable instability of these nuclei against particle emission. Measurements of the half-lives of⁴³Cr and⁴⁶Mn have been performed and the analysis of their measured beta-delayed proton spectra has given, through the isobaric multiplet mass equation, an empirical estimation of their masses. Half-lives of⁴⁴Cr,⁴³V,⁴⁷Fe and⁴⁶Fe have also been measured. A discussion of various mass predictions for nuclei at the proton drip-line is given.     

A minimal phenomenology for decay and resonance

We discuss in what sense the decay-scattering system is a minimal phenomenological theory for particle decay and resonance scattering.     

Synthesis and base promoted intramolecular nucleophilic reaction of 8-hydroxy-1,2,3,4-tetrachloro-9,9-dimethoxy-1α,4α,4aα,6,7,8β,8aα-hexahydro-1,4-methanonaphthalene-5(1H)-one

Catalytic hydrogenation of two substituted hexahydro-1,4-dimethanonaphthalene-5,8-diones results in reduction of the enedione carbon-carbon double bond with concomitant reduction of only one of the two chemically equivalent C=O groups. Reaction of one partially reduced product with base results in intramolecular addition to the carbon-carbon double bond.