Abstract: Systems and Apparatus for a personal ventilation system that provides a personalized column of clean air surrounding a user's space is presented. The personal ventilation system includes an air purifier with a fan and an annular gap downstream of the fan. The annular gap has an inner radius that is within 95% of the outer radius. The annular gap structure allows the air purifier to produce a column of air with an entrainment ratio lower than other commercially available fan. At a distance of 1.5 meters, the air purifier is configured to have an entrainment ratio of lower than 40%. The air purifier also has a removable filter located upstream of the fan. The ventilation system is capable of delivering highly-localized filtered air to a user or location.

Abstract: Systems and methods for customizing a removable filter in an air purifier. The removable filter may comprise multiple filter types, and the combination and characteristics of the filter types can be varied based on air-quality requirements. In some instances, the composition of a new filter can be determined based on data obtained from analysis of used filters. Additionally, filters can be personalized based on an individual user's health data, geographic location, and regional and local air-quality characteristics.

Abstract: The present disclosure provides methods, devices, systems and compositions for detecting nucleic acids in polymerase chain reaction assays, such as droplet digital polymerase chain reaction (ddPCR) assays. The present disclosure provides methods, devices, systems and compositions for detecting nucleic acids in ddPCR assays using intercalating dyes. A dual surfactant system with at least one fluorosurfactant and at least one non-ionic non-fluorosurfactant may be employed for droplet generation and nucleic acid detection.

Abstract: System, including methods and compositions, for making and using emulsions that include a silicone oil and a silicone surfactant. The emulsions may include aqueous droplets disposed in a continuous phase that includes a silicone oil and a silicone surfactant. The aqueous droplets may contain an analyte, optionally at partial occupancy, and/or a luminescent (e.g., photoluminescent) reporter. An assay of the analyte may be performed with the droplets. In some cases, signals may be detected from the droplets, and a characteristic of the analyte, such as an analyte level or activity, may be determined based on the signals.