Topologically enabled ultrahigh-Q guided resonances robust to out-of-plane scattering

© 2019, The Author(s), under exclusive licence to Springer Nature Limited. Because of their ability to confine light, optical resonators1–3 are of great importance to science and technology, but their performance is often limited by out-of-plane-scattering losses caused by inevitable fabrication imperfections4,5. Here we theoretically propose and experimentally demonstrate a class of guided resonances in photonic crystal slabs, in which out-of-plane-scattering losses are strongly suppressed by their topological nature. These resonances arise when multiple bound states in the continuum—each carrying a topological charge6—merge in momentum space and enhance the quality factors Q of all nearby resonances in the same band. Using such resonances in the telecommunication regime, we experimentally achieve quality factors as high as 4.9 × 105—12 times higher than those obtained with standard designs—and this enhancement remains robust for all of our samples. Our work paves the way for future explorations of topological photonics in systems with open boundary conditions and for their application to the improvement of optoelectronic devices in photonic integrated circuits

Histone Deacetylase Inhibitor Scriptaid Alleviated Neurological Dysfunction after Experimental Intracerebral Hemorrhage in Mice

Objectives. To investigate the role of Scriptaid in reducing brain injury after intracerebral hemorrhage (ICH) in mice. Methods. An ICH model was constructed by injecting autologous blood into the right basal ganglia in mice. The animals were administered 3.5 mg/kg of Scriptaid intraperitoneally after ICH. The hematoma volume and hemoglobin level were measured to examine hematoma resolution. A behavior test and brain edema and white matter injury examinations indicated brain injury after ICH. Results. Scriptaid treatment promoted hematoma resolution and reduced the hematoma volume 7 d after ICH compared with the vehicle group (P<0.05). Scriptaid treatment also alleviated the brain water content in the ipsilateral basal ganglia (P<0.05) and cortex (P<0.01) 3 d after ICH. In addition, Scriptaid improved neurological function recovery and alleviated white matter injury 35 d after ICH. Conclusions. Scriptaid can protect against brain injury after ICH and may be considered a new medical therapy method for ICH