"Umbrella" Structure Trisiloxane Surfactant: Synthesis and Application for Reverse Flotation of Phosphorite Ore in Phosphate Fertilizer Production

Phosphorite is generally used in the manufacture of phosphate fertilizer and plays a vital role in the development of agricultural and food production. Nonetheless, how to obtain phosphorite concentrates efficiently and sustainably has become an urgent problem. In this study, a newly designed trisiloxane surfactant, N-(2-Aminoethyl)-3-aminopropyltrisiloxane (AATS), has been prepared and utilized as an emerging collector for reverse flotation of phosphorite ore. Its collecting ability was compared with the conventional surfactant 1-dodecamine (DDA). In the collector concentration tests, AATS with lower concentrations showed stronger collecting ability for quartz. In the pH tests, AATS always performed better than DDA in the acidic or alkaline condition. In bench-scale flotation experiments, the P₂O₅ recovery of phosphorite concentrates with 150 g/t AATS was 10.77% higher than that with 300 g/t DDA, which proved that AATS can be applied to the sustainable production of phosphorite concentrates. For a 4000 t/d phosphorite ore processing plant, the profit could be increased 7,014,702.07 USD every year by using AATS as the collector. Therefore, this work provides a promising approach to enhance the production efficiency of phosphate fertilizer and to promote the sustainable development of agriculture.

[An experimental study of the influence of burn on the expressions of IFN-gamma and IL-4 in T lymphocytes and on the expression of IL-12 in macrophages in mice]

OBJECTIVE

To investigate the influence of burn on the expressions of IFN-gamma and IL-4 in T lymphocytes and on the expression of IL-12 in macrophages in mice.

METHODS

The mice inflicted by 12% TBSA burn on the back were employed as the model. The peritoneal macrophages (PMphis) were isolated and counted under light microscope (LM). The gene expression level of IL-12 P35 and P40 subunits was determined with RT-PCR. The ratio of spleen to body and splenic histology were also determined. Splenic T lymphocytes were isolated and the gene expression levels of IFN-gamma and IL-4 in the T lymphocytes were examined by RT-PCR.

RESULTS

(1) PMphis decreased significantly on 3 postburn day (PBD) and recovered quickly thereafter. (2) The gene expressions of IL-12 P35 and P40 subunits in PMphis were enhanced obviously. (3) Splenic index increased evidently and the karyokinesis phase increased in splenic lymphocytes. (4) The expressions of IFN-gamma and IL-4 in splenic T lymphocytes increased postburn.

CONCLUSION

The expressions of IFN-gamma and IL-4 in splenic T lymphocytes and the expressions of IL-12 in PMphis could be enhanced by burn injury.

Inhomogeneous distribution of brightness in the split-element filter

The inhomogeneous distribution of brightness in a split-element filter is discussed. This inhomogeneity is caused by the off-axis effect of the birefringent crystal and can seriously affect astronomical observations in the case of a large field of view. For example, the maximal brightness fluctuation is ~9.44% in a full-disk solar telescope whose maximal incident angle is 70 arcmin. We also discuss ways to avoid this disadvantage.

[Restrictive fragment length polymorphism analysis of gamma-crystallin in congenital cataract families]

Using gamma-crystallin gene probe P5G1, we investigated the RFLP in two large families of congenital cataracts and normal people, calculated the allelic gene frequency and defined the haplotypes by genetic linkage analysis. In accordance with foreign reports, TaqI/p5G1 detected 3 polymorphic sites, and the allelic gene frequency was close to that in foreign reports. However, foreign reports claimed that the haplotype P was linked to Coppock cataracts, but we did not find such linkage by haplotype analysis. The result suggests that not all the inherited cataracts are linked to gamma-crystallin gene, and the haplotype P should not be simply regarded as genetic marker in prenatal diagnosis.