COVID-19-Associated Ischemic Stroke in a Patient on Therapeutic Anticoagulation.

Introduction: The coronavirus disease 2019 (COVID-19) has been associated with a hypercoagulable state, increasing the risk for ischemic stroke. In select cases, patients are already on anticoagulation therapy. Such examples highlight the severity of COVID-19's hyperthrombotic state, and raise questions regarding optimal stroke prevention in these patients.

Induced-dichroism-excited atomic line filter at 532 nm.

The operation of a narrow-linewidth optical f ilter based on the 4P((1/2)) ? 8S((1/2)) excited-state transition in potassium vapor is reported. The 4P((1/2)) state is excited by a circularly polarized, 769.9-nm, 10-ns pulse from a dye laser.

Experimental demonstration of an excited-state Faraday filter operating at 532 nm.

We outline what is to our knowledge the first experimental demonstration of an excited-state Faraday filter. The filter consists of potassium vapor between crossed polarizers in a dc magnetic field and operates on the 4P((1/2)) ? 8S((1/2)) transition in potassium. The 4P((1/2)) state is populated by a linearly polarized, 10-ns light pulse from a dye laser operating at 769.

Injection-seeded optical parametric oscillator operating in the region of 486.1 nm.

An injection-seeded optical parametric oscillator operating near 486.1 nm has been demonstrated. The optical parametric oscillator was pumped by the third harmonic of a Nd:YAG laser and was frequency controlled by injecting an idler wave near 1313 nm from a Nd:YLF laser.