Although biliary complications occur somewhat frequently, central bisectionectomy in centrally located HCC can be performed safely to preserve liver volume.

We report a significant improvement of an approximate method of including electron Coulomb distortion in electron induced reactions at momentum transfers greater than the inverse of the size of the target nucleus. In particular, we have found a new parametrization for the elastic electron scattering phase shifts that works well at all electron energies greater than 300 M eV . As an illustration, we apply the improved approximation to the (e, e ′ p) reaction from medium and heavy nuclei. We use a relativistic "single particle" model for (e, e ′ p) as as applied to 208 P b(e, e ′ p) and to recently measured data at CE-BAF on 16 O(e, e ′ p) to investigate Coulomb distortion effects while examining the physics of the reaction. 25.30.Fj 25.70.Bc Typeset using REVT E X

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Direct experimental investigations of the low energy electronic structure of the Na2IrO3 iridate insulator are sparse and draw two conflicting pictures. One relies on flat bands and a clear gap, the other involves dispersive states approaching the Fermi level, pointing to surface metallicity. Here, by a combination of angle resolved photoemission, photoemission electron microscopy and x-ray absorption, we show that the correct picture is more complex and involves an anomalous band, arising from charge transfer from Na atoms to Ir-derived states. Bulk quasiparticles do exist, but in one of the two possible surface terminations the charge transfer is smaller and they remain elusive.The honeycomb iridate Na 2 IrO 3 represents an ideal example of a 5d5 system with complete removal of the orbital degeneracy by the spin-orbit interaction [1], and for this reason has been object of considerable attention in recent years. Magnetically, it has been proposed to realize the Kitaev model due to the hexagonal symmetry of the ab planes. The ground state was instead shown to have a zigzag antiferromagnetic (AF) order [2][3][4], accounted for by direct 5d-5d overlap [5], next nearest-neighbor coupling [4,[6][7][8][9], or possibly interorbital hopping [10]. Electronically, theoretical calculations have tentatively categorized this compound as a topological insulator [11,12]. Transport and optical measurements suggest rather a Mott insulator picture [8,[13][14][15], and an ongoing debate exists on whether spin-orbit coupling plays a decisive role [5,16,17] or a collaborative one [7,14,18,19] in opening the gap.The latter point essentially comes down to whether a relativistic approach with two effective J eff =1/2 and J eff =3/2 levels, as generally accepted in the description of the Ruddlesden-Popper series iridates [20], holds for this honeycomb lattice, or if spin-orbit coupling only "assists" a band gap. While experiments targeting the magnetic order have been numerous and exhaustive [2,3,13,21,22], measurements of the electronic structure have not been as successful. Unlike in perovskite iridates, which with a more symmetric crystal structure represent an ideal playground for angle resolved photoemission (ARPES) [23][24][25][26][27][28][29], photoemission data for Na 2 IrO 3 are limited to two instances [30,31], owing to the difficulty of obtaining sufficiently large cleaves.In one case, only remarkably flat bands with <100 meV bandwidth were observed, and no quasiparticles. The Fermi level was pinned at the top of a valence band with a density of states (DOS) reminiscent of a pseudogap [30]. In the other case, bands dispersing over more than 1 eV, more compatible with typical 5d bandwidths, were found, and more importantly a weak intensity in the vicinity of the Fermi level, which suggested surface metallicity [31]. In this Letter we use spatially-resolved ARPES to determine the electronic structure of Na 2 IrO 3 and its dependence upon the surface termination. We find that a clear quasiparticle at the Fermi level can be mea...

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