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Abstract:The mixed cationic collector cetyltrimethylammonium chloride (CTAC) and nonionic collector octanol (OCT) was found to exhibit a synergistic effect on the flotation and adsorption of muscovite. To understand the underlying synergistic mechanism, flotation, contact angle, surface tension, and adsorption measurements were carried out. The results obtained from flotation measurements indicated that the mixed CTAC/OCT exhibits a better collecting ability than CTAC or OCT. The recovery of muscovite with CTAC only rapidly decreased from 97.25% at pH 2.64 to 75.26% at pH 5.82, followed by a flat horizontal at a pH is higher than 6. In contrast, a high recovery of greater than 85% muscovite was observed using mixed CTAC/OCT at α CTAC = 0.67 (the mole ratio of CTAC:OCT = 2:1) over the investigated pH range. From the surface activity parameters (CMC, γ CMC , Γ max , A min ) estimated from surface measurements and interaction parameters (β m , β σ ), in addition to the micellar and interfacial compositions (x m 1 , x σ 1 ) obtained from the theory of regular solutions, a synergistic effect is evident in the mixed micelle and at the water/air interface. Moreover, the mixed CTAC/OCT at α CTAC = 0.67 exhibited the maximum synergistic interaction. The results obtained from surface tension measurements indicated that the mixed CTAC/OCT exhibits considerably higher surface activities compared to single CTAC or OCT. The contact angle results confirmed that the mixed CTAC/OCT is a better collector than the individual CTAC or OCT for the flotation of muscovite. According to the results obtained from adsorption experiments, compared with that of individual CTAC or OCT, the amounts of CTAC and OCT adsorbed on the muscovite surface are considerably increase in the mixed systems because of co-adsorption. Based on these results, the mixed CTAC/OCT exhibits a remarkable synergistic effect during the flotation and adsorption of muscovite.

In this study capillary zone electrophoresis (CZE) was used to analyze the poly(ethylene glycol)-modified bovine hemoglobin(PEG-bHb). The results show that CZE separated the subunit of bovine hemoglobin based on the number of PEG conjugating to the protein surface, which makes it possible to evaluate the degree of modification of hemoglobin subunit; meanwhile, it also reflected the stability of PEG attaching to hemoglobin after incubating with hydroxylamine, which makes it successful to detect the distribution of attachment site and evaluate the stability of PEG on the surface of hemoglobin. As a simple, fast and accurate method, CZE is suitable to monitor the production procedures and quality control of the final products of the PEG-bHb.

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The seasonal migration of wild aquatic birds plays a critical role in the maintenance, transmission, and incursion of the avian influenza virus (AIV). AIV surveillance was performed during 2020–2021 in two national nature reserves with abundant wild bird resources in Yunnan, China. Four H5N8 AIVs isolates from the common crane were identified by next-generation sequencing. Phylogenetic analysis demonstrated that all eight gene segments of these H5N8 AIVs belonged to clade 2.3.4.4b high-pathogenic AIV (HPAIV) and shared high nucleotide sequence similarity with the strains isolated in Hubei, China, and Siberia, Russia, in 2020–2021. The H5N8 HPAIVs from common cranes were characterized by both human and avian dual-receptor specificity in the hemagglutinin (HA) protein. Moreover, possessing the substitutions contributes to overcoming transmission barriers of mammalian hosts in polymerase basic 2 (PB2), polymerase basic protein 1 (PB1), and polymerase acid (PA), and exhibiting the long stalk in the neck region of the neuraminidase (NA) protein contributes to adaptation in wild birds. Monitoring AIVs in migratory birds, at stopover sites and in their primary habitats, i.e., breeding or wintering grounds, could provide insight into potential zoonosis caused by AIVs.