RESUMEN
In this work, we revisit the dynamics of carbon monoxide molecular chemisorption on Cu(110) by using quasi-classical trajectory calculations. The molecule-surface interaction is described through an atomistic neural network approach based on Density Functional Theory calculations using a nonlocal exchange-correlation (XC) functional that includes the effect of long-range dispersion forces: vdW-DF2 [Lee et al. Phys. Rev. B, 82, 081101 (2010)]. With this approach, we significantly improve the agreement with experiments with respect to a similar previous study based on a semi-local XC functional. In particular, we obtain excellent agreement with molecular beam experimental data concerning the dependence of the initial sticking probability on surface temperature and impact energy at normal incidence. For off-normal incidence, our results also reproduce two trends observed experimentally: (i) the preferential sticking for molecules impinging parallel to the [1Ì10] direction compared to [001] and (ii) the change from positive to negative scaling as the impact energy increases. Nevertheless, understanding the origin of some remaining quantitative discrepancies with experiments requires further investigations.
RESUMEN
A high dimensional and accurate atomistic neural network potential energy surface (ANN-PES) that describes the interaction between one O2 molecule and a highly oriented pyrolytic graphite (HOPG) surface has been constructed using the open-source package (aenet). The validation of the PES is performed by paying attention to static characteristics as well as by testing its performance in reproducing previous ab initio molecular dynamics simulation results. Subsequently, the ANN-PES is used to perform quasi-classical molecular dynamics calculations of the alignment-dependent scattering of O2 from HOPG. The results are obtained for 200 meV O2 molecules with different initial alignments impinging with a polar incidence angle with respect to the surface normal of 22.5° on a thermalized (110 and 300 K) graphite surface. The choice of these initial conditions in our simulations is made to perform comparisons to recent experimental results on this system. Our results show that the scattering of O2 from the HOPG surface is a rather direct process, that the angular distributions are alignment dependent, and that the final translational energy of end-on molecules is around 20% lower than that of side-on molecules. Upon collision with the surface, the molecules that are initially aligned perpendicular to the surface become highly rotationally excited, whereas a very small change in the rotational state of the scattered molecules is observed for the initial parallel alignments. The latter confirms the energy transfer dependence on the stereodynamics for the present system. The results of our simulations are in overall agreement with the experimental observations regarding the shape of the angular distributions and the alignment dependence of the in-plane reflected molecules.
RESUMEN
Presentamos un paciente con Lupus Eritematoso Sistémico (LES) tratado previamente con Rituximab y Micofenolato Mofetilo que desarrolló una criptococosis meníngea. Los pacientes con LES presentan múltiples defectos en su sistema inmune (SI) que, sumados a los producidos por los tratamientos inmunosupresores, predisponen a infecciones, entre ellas, a las causadas por gérmenes oportunistas. La meningitis por criptococo es una rara y severa complicación en estos pacientes. Rituximab produce una serie de cambios en el SI actuando sobre los linfocitos B, mientras que micofenolato actúa tanto sobre las células T como B. Las alteraciones inmunológicas presentes en nuestro paciente serían producto de la sumatoria de efectos de ambas drogas que explicarían la infección por Criptococcus neoformans.
We presented a systemic lupus erythematosus (SLE) patient previously treated with rituximab and mycophenolate who developed cryptococcal meningitis. SLE patients have multiple defects in the immunity system in addition to the additive effects of immunosuppressive treatments, which predispose to opportunistic infections. Cryptococcal meningitis is a rare and severe complication in SLE patients. Rituximab produces a series of changes in the immune system by acting on B cells, while mycophenolate produces its actions by acting on T and B cells. The immunology system defects in our patient could be done because the additive effects of two drugs that could explain the Cryptococcus neoformans infection.
