Clinical characteristics and mortality risk among critically ill patients with COVID-19 owing to the B.1.617.2 (Delta) variant in Vietnam: A retrospective observational study.

Background: SARS-CoV-2 Delta variant caused a large number of COVID-19 cases in many countries, including Vietnam. Understanding mortality risk factors is crucial for the clinical management of severe COVID-19.

Methods: We conducted a retrospective study at an intensive care center in Ho Chi Minh City that urgently built by Bach Mai Hospital during the COVID-19 outbreak in Vietnam, when the Delta variant predominated.

Enhancing the light extraction efficiency of AlInN nanowire ultraviolet light-emitting diodes with photonic crystal structures.

In this paper, AlInN nanowire ultraviolet light-emitting diodes (LEDs) with emission at ∼299 nm have been successfully demonstrated. We have further studied the light extraction properties of these nanowire LEDs using photonic crystal structures with square and hexagonal lattices of nanowires. The light extraction efficiency (LEE) of the periodic nanowire LED arrays was found to be significantly increased as compared to random nanowire LEDs.