RESUMO
Visceral leishmaniasis is the most severe form of leishmaniasis, caused by the obligate intracellular protozoan parasites Leishmania donovani or L. infantum, transmitted by the bite of phlebotomine sand fly. Visceral leishmaniasis is a disease of lowlands and uncommon in highlands. We report a case of visceral leishmaniasis in 13-year-old female patient from a village of Arghakhanchi situated at an altitude of 1200 m.
RESUMO
The large tunability of band gaps and optical absorptions of armchair MoS2 nanoribbons of different widths under bending is studied using density functional theory and many-body perturbation GW and Bethe-Salpeter equation approaches. We find that there are three critical bending curvatures, and the non-edge and edge band gaps generally show a non-monotonic trend with bending. The non-degenerate edge gap splits show an oscillating feature with ribbon width n, with a period [Formula: see text], due to quantum confinement effects. The complex strain patterns on the bent nanoribbons control the varying features of band structures and band gaps that result in varying exciton formations and optical properties. The binding energy and the spin singlet-triplet split of the exciton forming the lowest absorption peak generally decrease with bending curvatures. The large tunability of optical properties of bent MoS2 nanoribbons is promising and will find applications in tunable optoelectronic nanodevices.