Zinc Recovery from Wulagen Sulfide Flotation Plant Tail by Applying Ether Amine Organic Collectors.

Separating oxidized zinc minerals from flotation tailings is always a challenge. In this study, a flotation tailing from Wulagen zinc mine in China (Zn grade < 1%) was processed using froth flotation with combinations of amines (OPA 10, OPA 1214, OPA 13, DDA) and Na2S to study the effects of these amines on the zinc recovery as well as their interactions with other reagents, aiming to screen out a proper reagent scheme to improve zinc separation from extremely low-grade zinc flotation tailings. The results show that different amines led to different flotation performance, and the collectors were ranked as OPA 1214, OPA 13, OPA 10 and DDA in a decreasing order based on flotation collectivity and selectivity. An increase in the concentration of each collector increased the zinc recovery but reduced the concentrate zinc grade. Interactions were also observed between different amines and Na2S and Na2SiO3, and OPA 1214 outdid the others in saving the usage of both the Na2S and Na2SiO3. The measured adsorption of collector onto smithsonite was found to correlate well with flotation test results. It was concluded that hydrocarbon chains can be held accountable for the difference in the flotation performance with different amines. The longer the hydrocarbon chain, the stronger the hydrophobic association ability of amine, which is conducive to the selective amine adsorption onto sulfurized smithsonite particles and hence the smithsonite flotation.

Hyperhomocysteinemia may aggravate abdominal aortic aneurysm formation by up-regulating RASSF2.

Abdominal aortic aneurysm (AAA) is a fatal cardiovascular disorder with high mortality and morbidity rates. To date, no drug has shown to significantly alleviate the risk of AAA. Previous studies have indicated that hyperhomocysteinemia (HHcy) significantly increases the incidence of AAA by disrupting endothelial cell homeostasis; however, the potential molecular mechanisms require clarification. Herein, we aimed to integrate transcriptomics analysis and molecular biology experiments to explore the potential molecular targets by which HHcy may increase the incidence of AAA. We integrated two AAA data profiles (GSE57691 and GSE7084) based on previously published microarray ribonucleic acid sequencing (RNAseq) data from the GEO database. Additionally, 500 µM homocysteine-treated human aorta endothelium cells microarray dataset (GSE175748) was downloaded and processed. Subsequently, single-cell RNA-seq profiles of the aortic aneurysms (GSE155468) were downloaded, scaled, and processed for further analysis. The microarray profiles analysis demonstrated that the Ras association domain family member 2 (RASSF2) and interleukin (IL)-1ß are potentially the target genes involved in the HHcy-mediated aggravation of AAA formation. Single-cell RNAseq analysis revealed that RASSF2 might impair endothelial cell function by increasing inflammatory cell infiltration to participate in AAA formation. Finally, we conducted reverse transcription quantitative polymerase chain reaction and immunofluorescence analysis to validate the up-regulated mRNA expression of RASSF2 (p = 0.008) and IL-1ß (p = 0.002) in AAA tissue compared to control tissue. Immunofluorescence staining revealed overexpression of RASSF2 protein in AAA tissue sections compared to control tissue (p = 0.037). Co-localization of RASSF2 and the aortic endothelium cell marker, CD31, was observed in tissue sections, indicating the potential involvement of RASSF2 in aortic endothelial cells. To summarise, our preliminary study revealed that HHcy may worsen AAA formation by up-regulating the expression of RASSF2 and IL-1ß in aortic endothelium cells.

Asymmetric aldol reactions catalyzed by tryptophan in water.

Tryptophan was shown to be able to catalyze direct aldol reactions between various cyclic ketones and aromatic aldehydes in water with high enantioselectivity.

Mixed hemimicelles solid-phase extraction based on sodium dodecyl sulfate-coated nano-magnets for selective adsorption and enrichment of illegal cationic dyes in food matrices prior to high-performance liquid chromatography-diode array detection detection.

In this study, mixed hemimicelles solid-phase extraction (MHSPE) based on sodium dodecyl sulfate (SDS) coated nano-magnets Fe3O4 was investigated as a novel method for the extraction and separation of four banned cationic dyes, Auramine O, Rhodamine B, Basic orange 21 and Basic orange 22, in condiments prior to HPLC detection. The main factors affecting the extraction of analysts, such as pH, surfactant and adsorbent concentrations and zeta potential were studied and optimized. Under optimized conditions, the proposed method was successful applied for the analysis of banned cationic dyes in food samples such as chili sauce, soybean paste and tomato sauce. Validation data showed the good recoveries in the range of 70.1-104.5%, with relative standard deviations less than 15%. The method limits of determination/quantification were in the range of 0.2-0.9 and 0.7-3µgkg(-1), respectively. The selective adsorption and enrichment of cationic dyes were achieved by the synergistic effects of hydrophobic interactions and electrostatic attraction between mixed hemimicelles and the cationic dyes, which also resulted in the removal of natural pigments interferences from sample extracts. When applied to real samples, RB was detected in several positive samples (chili powders) within the range from 0.042 to 0.177mgkg(-1). These results indicate that magnetic MHSPE is an efficient and selective sample preparation technique for the extraction of banned cationic dyes in a complex matrix.

Fast and simultaneous determination of eleven synthetic color additives in flour and meat products by liquid chromatography coupled with diode-array detector and tandem mass spectrometry.

In this study, an efficient, fast and sensitive method for the simultaneous determination of eleven synthetic color additives (Allura red, Amaranth, Azo rubine, Brilliant blue, Erythrosine, Indigotine, Ponceau 4R, New red, Sunset yellow, Quinoline yellow and Tartrazine) in flour and meat foodstuffs is developed and validated using HPLC coupled with DAD and MS/MS. The color additives were extracted with ammonia-methanol and was further purified with SPE procedure using Strata-AW column in order to reduce matrix interference. This HPLC-DAD method is intended for a comprehensive survey of color additives in foods. HPLC-MS/MS method was used as the further confirmation and identification. Validation data showed the good recoveries in the range of 75.2-113.8%, with relative standard deviations less than 15%. These methods are suitable for the routine monitoring analysis of eleven synthetic color additives due to its sensitivity, reasonable time and cost.

[Development of the new measuring & training device for eustachian tube opening function].

This paper presents to you the principles, composition, features and applications of ET-100 measuring-training device for eustachian tube opening function.