Silicon photonics efficient fiber coupler based on a metastructure with a minimum feature size of 150 nm.

We propose a silicon photonics fiber coupler consisting of a metastructure containing a through-hole array and a partially etched grating to obtain high efficiency. Using an evolution optimization algorithm, we optimized 121 structural parameters and achieved a minimum feature size of 150 nm, which greatly simplifies the fabrication using wafer-scale foundry services. We designed two structures, one achieving an 86% coupling efficiency into a single fiber, and the other exhibiting a full flat spectrum in the C band.

[Cesarean section in a patient with severe mitral stenosis after mitral valve replacement].

A 30-year-old woman with mitral stenosis after mitral valve replacement was scheduled for cesarean section at 28 weeks and 6 days of pregnancy. Cesarian section was decided at a conference of obstetrics, cardiac surgery, neonatology and anesthesiology. Anesthesia was successfully managed with epidural block and pulmonary arterial pressure monitoring.

[Anesthesia for anticoagulated patients].

Background: Anticoagulated patients who undergo surgry have been increasing in number. They may develop thrombo-embolic and/or bleeding complications.

Methods: We studied 79 patients retrospectively who had undergone elective surgery from April 2002 through December 2003.