Asymmetric Free-Space Light Transport at Nonlinear Metasurfaces.

Asymmetric light transport has significantly contributed to fundamental science and revolutionized advanced technology in various aspects such as unidirectional photonic devices, optical diodes, and isolators. While metasurfaces mold wave fronts at will with an ultrathin flat optical element, asymmetric transport of light cannot be fundamentally achieved by any linear system including linear metasurfaces. We report asymmetric transport of free-space light at nonlinear metasurfaces upon transmission and reflection.

Macroscale Transformation Optics Enabled by Photoelectrochemical Etching.

Photoelectrochemical etching of silicon can be used to form lateral refractive index gradients for transformation optical devices. This technique allows the fabrication of macroscale devices with large refractive index gradients. Patterned porous layers can also be lifted from the substrate and transferred to other materials, creating more possibilities for novel devices.

A multicenter trial of the effectiveness of zeta-globin enzyme-linked immunosorbent assay and hemoglobin H inclusion body screening for the detection of alpha0-thalassemia trait.

Routine laboratories use a hemoglobin H (HbH) screen to detect alpha-thalassemia carriers of fatal hemoglobin Bart's hydrops fetalis. This test is laborious and has sensitivity concerns. A commercial zeta-globin enzyme-linked immunosorbent assay (ELISA) is effective in detecting Southeast Asian (SEA) alpha-thalassemia.

Prevalence of thalassemia in patients with microcytosis referred for hemoglobinopathy investigation in Ontario: a prospective cohort study.

In Ontario, Canada, beta-thalassemia is easily detected through measurement of hemoglobin A2, but most laboratories do not do exhaustive DNA investigations for alpha-thalassemia. Therefore, the prevalence of thalassemia in microcytic samples for hemoglobinopathy investigation in Ontario is unknown. To address this, we performed a prospective cohort study in which samples referred for hemoglobinopathy investigation were also evaluated for alpha-thalassemia by DNA testing.