Comparison of Lagrangian-Eulerian and Eulerian-Eulerian Approaches for Particle Laden Free Surface Flow by Means of Lattice Boltzmann Method

The aim of this study is a comparison of Lagrangian-Eulerian and Eulerian-Eulerian numerical approach for the simulation of fluid-particles interaction. Within the study the immersed particles are restricted to have spherical shapes and are equal or smaller than the resolution of the computational mesh. The interaction between fluid and particles is performed using the immersed boundary method and the free surface flow of an incompressible fluid is simulated using the lattice Boltzmann method. Both approaches are compared within two test problems. Firstly, the swarm of particles falling in the fluid, and secondly, casting of the fluid with dispersed particles into a mold. Both tests showed good qualitative and quantitative agreement of mentioned approaches

First-principles study of As interstitials in GaAs: Convergence, relaxation, and formation energy

Convergence of density-functional supercell calculations for defect formation energies, charge transition levels, localized defect state properties, and defect atomic structure and relaxation is investigated using the arsenic split interstitial in GaAs as an example. Supercells containing up to 217 atoms and a variety of {\bf k}-space sampling schemes are considered. It is shown that a good description of the localized defect state dispersion and charge state transition levels requires at least a 217-atom supercell, although the defect structure and atomic relaxations can be well converged in a 65-atom cell. Formation energies are calculated for the As split interstitial, Ga vacancy, and As antisite defects in GaAs, taking into account the dependence upon chemical potential and Fermi energy. It is found that equilibrium concentrations of As interstitials will be much lower than equilibrium concentrations of As antisites in As-rich, $n$-type or semi-insulating GaAs.Comment: 10 pages, 5 figure

Blocking c-Jun-N-terminal kinase signaling can prevent hearing loss induced by both electrode insertion trauma and neomycin ototoxicity.

Neomycin ototoxicity and electrode insertion trauma both involve activation of the mitogen activated protein kinase (MAPK)/c-Jun-N-terminal kinase (JNK) cell death signal cascade. This article discusses mechanisms of cell death on a cell biology level (e.g. necrosis and apoptosis) and proposes the blocking of JNK signaling as a therapeutic approach for preventing the development of a permanent hearing loss that can be initiated by either neomycin ototoxicity or electrode insertion trauma. Blocking of JNK molecules incorporates the use of a peptide inhibitor (i.e. D-JNKI-1), which is specific for all three isoforms of JNK and has been demonstrated to prevent loss of hearing following either electrode insertion trauma or loss of both hearing and hair cells following exposure to an ototoxic level of neomycin. We present previously unpublished results that control for the effect of perfusate washout of aminoglycoside antibiotic by perfusion of the scala tympani with an inactive form of D-JNKI-1 peptide, i.e. JNKI-1(mut) peptide, which was not presented in the original J. Neurosci. article that tested locally delivered D-JNKI-1 peptide against both noise- and neomycin-induced hearing loss (i.e. Wang, J., Van De Water, T.R., Bonny, C., de Ribaupierre, F., Puel, J.L., Zine, A. 2003a. A peptide inhibitor of c-Jun N-terminal kinase protects against both aminoglycoside and acoustic trauma-induced auditory hair cell death and hearing loss. J. Neurosci. 23, 8596-8607). D-JNKI-1 is a cell permeable peptide that blocks JNK signaling at the level of the three JNK molecular isoforms, which when blocked prevents the increases in hearing thresholds and the loss of auditory hair cells. This unique therapeutic approach may have clinical application for preventing: (1) hearing loss caused by neomycin ototoxicity; and (2) the progressive component of electrode insertion trauma-induced hearing loss

Endoscopic endonasal resection of esthesioneuroblastoma: a multicenter study

This study reports the combined experience of the University of Miami and University of Pittsburgh with endoscopic endonasal resection of esthesioneuroblastoma (ENB). A retrospective case series review was performed in a tertiary care university hospital. Twenty-three patients, 16 men and 7 women, were reviewed. Mean age was 56.6 years (15-79 years). Nineteen patients received primary endoscopic endonasal anterior skull base resection. Of these, the modified Kadish stage at presentation was A in 2 patients, B in 11 patients, C in 5 patients, and D in 1 patient. Three patients had revision surgeries for recurrent tumors. The main outcome measures were complete resection and margin assessment, short-term and long-term complications, and recurrence rate. Complete resection and negative intraoperative resection margins were achieved endoscopically in 17 of the primarily treated cases. The two other cases had one patient that required an additional craniotomy approach to complete the resection of a positive lateral dual margin, another patient had positive margins at the orbital apex. All patients tolerated the endoscopic procedure very well with no meningitis. There were four cerebral spinal fluid leaks. Mean follow-up period for the primarily treated cases was 45.2 months (11-152 months), all were disease free at the most recent available follow-up. In experienced hands and carefully selected patients, endoscopic resection of ENB respects the principles of oncologic surgery, providing an adequate exposure for margin assessment as well as reliable reconstruction of the anterior skull defect with a relatively low morbidity