Alkyl amines are widely used as cationic collectors in flotation. In this work, the flotation foaming behaviors of alkyl amines, including dodecylamine (DDA), din -hexylamine (DHA), octadecylamine (ODA), oleylamine (OLA), in the presence or absence of quartz were investigated by a new approach, "foam analyzer". The effects of pH, reagent dosage, concentration of quartz powder, and particle size on foaming property and stability of bubble were explored, and the physical model of foam structure evolution was established. The adsorption mechanism of amines on quartz surface was studied from molecular structure, surface tension, zeta potential, charging mode, and adsorption form. The results show the foam stability of four amine collectors as follows: OLA > ODA > DHA > DDA. In the range of pH=6-10, the foam properties of the four amines are better. Under the same conditions, the longer carbon chain of aliphatic amine, the more unsaturated bonds, the fewer hydrogen atoms of the amine group, and the corresponding foam properties are better. When the concentration of quartz powder is 8-10%, the foaming and stability of the foam of four kinds amines are the best, The finer quartz powder particle size, the more stable the amine foam and the stronger the foamability.

Multicellular intestinal nematode parasites can cross the epithelial barrier potentially causing tissue damage and release of danger associated molecular patterns (DAMPs) that may promote type 2 responses and host protective immunity. We investigated whether adenosine specifically binding the A2B adenosine receptor (A2BAR) on epithelial cells played an important role in driving intestinal immunity. Specific blockade of epithelial cell A2BAR inhibited the host protective memory response to the enteric helminth, Heligmosomoides polygyrus bakeri, including disruption of granuloma development at the host:parasite interface during the transient tissue dwelling larval stage. Memory T cell development was blocked during the primary response and transcriptional analyses revealed profound impairment of A2BAR signaling in epithelial cells and reduced type 2 markers by 24 hours after inoculation. Extracellular ATP was visualized by 24 hours after inoculation and shown in CD39 deficient mice to be critical for the adenosine production mediating initiation of type 2 immunity.