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About 90 % rare earth minerals and many other valuable minerals are heaped as iron tailings without comprehensive utilization. In order to comprehensively recover these valuable minerals, in a view of the valuable ore type of Baotou Steel tailing and embedded features, valuable components flow and their respective recovery coupling relationship in beneficiation flowsheet were analyzed; process flows and parameters which could give consideration to four kinds of components were determined. TFe, rare earth oxide (REO), niobium and fluorite recoveries could reach 72.70 %, 81.84 %, 78.58 % and 60.18 % in low-intensity/high-intensity magnetic separation, respectively. High-intensity magnetic concentration was treated by REO direct flotation; the recovery is 75.43 %, on the base of which Fe could be separated completely from Nb. The underflow was treated by reduction roasting-low-intensity magnetic separation. And the relationship between the recoveries of these valuable components was also discussed. [ABSTRACT FROM AUTHOR]

The cytochrome CYP1A1 gene has been implicated in the etiology of oral cancer. However, the results have been inconsistent. In this study, a meta-analysis was performed to clarify the associations of polymorphisms in CYP1A1 gene with oral cancer risk. Published literatures from PubMed, MEDLINE, EMBASE, and China National Knowledge infrastructure (CNKI) databases were retrieved. A total of 12 studies were included in this meta-analysis. We found that significant positive associations between CYP1A1* 2A polymorphism and oral cancer risk in recessive model (CC vs. TC + TT, OR = 1.93), dominant model (CC + TC vs. TT, OR = 1.33), and additive model (CC vs. TT, OR = 1.97). In subgroup analysis based on the ethnicity of study population, significant associations were found in all three genetic models for Asians (recessive OR = 2.29, 95 % CI = 1.42-3.71; dominant OR = 1.54, 95 % CI = 1.03-2.31; additive OR = 2.39, 95 % CI = 1.47-3.88) but not non-Asians. For the smoking stratification, the result indicated a significant association between CYP1A1* 2A polymorphism and oral cancer among the smoking subjects (OR = 1.83, 95 % CI = 1.47-2.26). This meta-analysis indicated a marked association of CYP1A1* 2A polymorphisms with oral cancer risk, particularly among Asians, whereas there were significant interactions between the polymorphisms and cigarette smoking on oral cancer risk. [ABSTRACT FROM AUTHOR]

Two different types of chalcopyrite (pyritic chalcopyrite and porphyry chalcopyrite) were bioleached with Acidithiobacillus ferrooxidans ATF6. The bioleaching of the pyritic chalcopyrite and porphyry chalcopyrite is quite different. The copper extraction reaches 46.96% for the pyritic chalcopyrite after 48-d leaching, but it is only 14.50% for the porphyry chalcopyrite. Proper amounts of initial ferrous ions can improve the efficiency of copper extraction for the two different types of chalcopyrite. The optimum dosage of ferrous ions for the pyritic chalcopyrite and porphyry chalcopyrite is different. The adsorption of ATF6 on the pyritic chalcopyrite and porphyry chalcopyrite was also studied in this paper. It is found that ATF6 is selectively adsorbed by the two different types of chalcopyrite; the higher adsorption onto the pyritic chalcopyrite than the porphyry chalcopyrite leads to the higher copper dissolution rate of the pyritic chalcopyrite. In addition, the zeta-potential of chalcopyrite before and after bioleaching further confirms that ATF6 is more easily adsorbed onto the pyritic chalcopyrite. [ABSTRACT FROM AUTHOR]