Submillimetric gradient-echo images (eg, 3DFT-CISS) should always be used to exclude aplasia or hypoplasia of the cochlear branch of the VCN in all cochlear implant candidates and patients with congenital deafness. This entity, which can occur with or without associated labyrinthine malformation, should be confirmed in two planes.

We present the ab initio potential-energy surfaces of the NH-NH complex that correlate with two NH molecules in their 3 ⌺ − electronic ground state. Three distinct potential-energy surfaces, split by exchange interactions, correspond to the coupling of the S A = 1 and S B = 1 electronic spins of the monomers to dimer states with S = 0, 1, and 2. Exploratory calculations on the quintet ͑S =2͒, triplet ͑S =1͒, and singlet ͑S =0͒ states and their exchange splittings were performed with the valence bond self-consistent-field method that explicitly accounts for the nonorthogonality of the orbitals on different monomers. The potential surface of the quintet state, which can be described by a single Slater determinant reference function, was calculated at the coupled cluster level with single and double excitations and noniterative treatment of the triples. The triplet and singlet states require multiconfiguration reference wave functions and the exchange splittings between the three potential surfaces were calculated with the complete active space self-consistent-field method supplemented with perturbative configuration interaction calculations of second and third orders. Full potential-energy surfaces were computed as a function of the four intermolecular Jacobi coordinates, with an aug-cc-pVTZ basis on the N and H atoms and bond functions at the midpoint of the intermolecular vector R. An analytical representation of these potentials was given by expanding their dependence on the molecular orientations in coupled spherical harmonics, and representing the dependence of the expansion coefficients on the intermolecular distance R by the reproducing kernel Hilbert space method. The quintet surface has a van der Waals minimum of depth D e = 675 cm −1 at R e = 6.6a 0 for a linear geometry with the two NH electric dipoles aligned. The singlet and triplet surfaces show similar, slightly deeper, van der Waals wells, but when R is decreased the weakly bound NH dimer with S = 0 and S = 1 converts into the chemically bound N 2 H 2 diimide ͑also called diazene͒ molecule with only a small energy barrier to overcome.

Five patients with biopsy-proven craniofacial fibrous dysplasia underwent MRI with T1- and T2-weighted sequences and a gadolinium-enhanced T1-weighted spin-echo sequence. Low to intermediate signal intensity was usually seen in the largest part of the lesion on both spin-echo sequences, but smaller regions of hyperintensity on T1- and T2-weighted images and intermediate signal intensity throughout a lesion on T1-weighted images were also seen. All lesions enhanced but only two became iso- or hyperintense compared to fat. High clinical and pathological activity in three cases correlated with high signal intensity on both spin-echo sequences and with strong enhancement in two of the three. The presence of large veins or sinusoids on pathological examination did not correlate with the enhancement pattern.

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Context. Over the next few years, ALMA and Herschel missions will perform high spatial and spectral resolution studies at infrared and sub-millimeter wavelengths. This will provide much greater detail about the composition and evolution of molecules in space. Modeling of the spectra will require accurate radiative and collisional rates for species of astrophysical interest. Aims. We calculate ro-vibrational excitation rate coefficients of SO by He, useful for studies of high-temperature environments. Methods. A new accurate three dimensional (3D) potential energy surface was calculated for the SO-He system which explicitly takes into account the r-dependence of the SO vibration as well as the R-distance and θ angle which describe the relative position of the collision partners. The dynamics calculations were performed according to the VCC-IOS approximation. Results. The new rate coefficients between the ro-vibrational levels are calculated for temperatures from 300 K to 800 K.