Native IBV (B/Jiangsu/10/03) Antigen

Highly transmissible influenza viruses (IV) must remain stable and infectious under a wide range of environmental conditions following release from the respiratory tract into the air. Understanding how expelled IV persist in the environment is critical to limiting the spread of these viruses. Little is known about how the stability of different IV in expelled aerosols is impacted by exposure to environmental stressors, such as relative humidity (RH). Given that not all IV are equally capable of efficient airborne transmission in people, we anticipated that not all IV would respond uniformly to ambient RH. Therefore, we have examined the stability of human-pathogenic seasonal and avian IV in suspended aerosols and stationary droplets under a range of RH conditions. H3N2 and influenza B virus (IBV) isolates are resistant to RH-dependent decay in aerosols in the presence of human airway surface liquid, but we observed strain-dependent variations in the longevities of H1N1, H3N2, and IBV in droplets. Surprisingly, low-pathogenicity avian influenza H6N1 and H9N2 viruses, which cause sporadic infections in humans but are unable to transmit person to person, demonstrated a trend toward increased sensitivity at midrange to high-range RH. Taken together, our observations suggest that the levels of vulnerability to decay at midrange RH differ with virus type and host origin. IMPORTANCE The rapid spread of influenza viruses (IV) from person to person during seasonal epidemics causes acute respiratory infections that can lead to hospitalizations and life-threatening illness. Atmospheric conditions such as relative humidity (RH) can impact the viability of IV released into the air. To understand how different IV are affected by their environment, we compared the levels of stability of humanpathogenic seasonal and avian IV under a range of RH conditions and found that highly transmissible seasonal IV were less sensitive to decay under midrange RH conditions in droplets. We observed that certain RH conditions can support the persistence of infectious viruses on surfaces and in the air for extended periods of time. Together, our findings will facilitate understanding of factors affecting the persistence and spread of IV in our environment.

This paper reports a novel electromagnetic micropump (EMP) that only uses one vibrating integrated butterfly valve (IBV) to manipulate microfluid directly. The IBV, composed of a Polyimide (PI) slice, a moving magnet and elastic silica gel diaphragm, could open or close periodically stimulated by external alternating magnetic field. The micropump is instantaneous fluid pressure-dependent for simple structure by integrating the butterfly valve and moving parts into one valve. In the suction mode, the positive instantaneous pressure pushes the valve, driving the fluid crossing the valve. While in the expelling mode, the negative instantaneous pressure compresses the slice and closes the valve, pushing fluid out. The test results not only show a frequency-dependent flow rate relationship and determine a resonance frequency of 15 Hz, but also give linear curves between flow rate/backpressure and applied current. Furthermore, the designed micropump exhibits a maximum flow rate and backpressure of 9.47 mL/min and 70.5 mmH(2)O respectively. For its simplicity, this novel micropump technology could be scaled down easily, which could be further integrated and applied in a microsystem. (C) 2020 Elsevier B.V. All rights reserved.