Abstract: The present disclosure belongs to the technical field of biological products for veterinary medicine, and specifically relates to a recombinant foot-and-mouth disease virus (FMDV) with a reduced immunosuppressive activity, a preparation method and use thereof, and a recombinant vaccine strain. According to the present disclosure, it is firstly discovered that FMDV 3B protein has an immunosuppressive function, and key sites for exerting the immunosuppressive function are found. A recombinant FMDV vaccine strain with a lost immunosuppressive function in FMDV 3B protein is constructed by introducing amino acid mutations into three repeated copies of FMDV 3B protein.

Abstract: Disclosed herein are integrated preparation and detection devices for studying biomass-burning aerosols, where the devices include a micro-fluidized bed reactor (MFBR), a transmission line, and an on-line detection unit that are connected in sequence. The MFBR may include a pyrolysis reactor and a pyrolysis furnace; the pyrolysis reactor may include a thermocouple, an introduction tube, and quartz sands; the on-line detection unit may be an on-line photoionization mass spectrometer; and the photoionization mass spectrometer may include a laser desorption system, a laser ionizer and a light energy ionizer. Devices of the present disclosure are beneficial to retain the original state of aerosol particles, and the fixed MFBR can realize rapid pyrolysis of a biomass due to its high and stable heat conduction efficiency, which is beneficial to studying the formation mechanism of aerosol particles.

Abstract: Disclosed herein are integrated preparation and detection devices for studying biomass-burning aerosols, where the devices include a micro-fluidized bed reactor (MFBR), a transmission line, and an on-line detection unit that are connected in sequence. The MFBR may include a pyrolysis reactor and a pyrolysis furnace; the pyrolysis reactor may include a thermocouple, an introduction tube, and quartz sands; the on-line detection unit may be an on-line photoionization mass spectrometer; and the photoionization mass spectrometer may include a laser desorption system, a laser ionizer and a light energy ionizer. Devices of the present disclosure are beneficial to retain the original state of aerosol particles, and the fixed MFBR can realize rapid pyrolysis of a biomass due to its high and stable heat conduction efficiency, which is beneficial to studying the formation mechanism of aerosol particles.