Research on the Dealkalization Treatment of Bauxite Residue and Deep Extraction of Alumina.

Bauxite residue is the bulk solid waste generated by the alumina industry, and the environmental treatment of bauxite residue has always been a focus of attention. In this study, in the high calcium system, the bauxite residue was intensively digestion by the calcification-carbonation method, and the mole ratio of solution, the mass ratio of CaO/SiO2 of the digestion process were changed, so that the high-efficiency dealkalization of bauxite residue was realized and the aluminum oxide in bauxite residue was deeply extracted. The experimental results showed that the calcification process could achieve the recovery of 17.83% alumina at 260°C, reaction duration of 60 min, liquid-solid ratio = 5:1, the mass ratio of CaO/SiO2 = 3.5, and 200 g/L NaOH solution. The whole process can recover 49.61% of alumina from bauxite residue, and 94.4% of alkali in bauxite residue can be removed.

Liraglutide Attenuates Restenosis After Vascular Injury in Rabbits With Diabetes Via the TGF-ß/Smad3 Signaling Pathway.

Background: Lower limb ischemia due to arterial stenosis is a major complication in patients with diabetes mellitus (DM). Liraglutide is a long-acting analogue of a glucagon-like peptide 1 (GLP-1) receptor agonist used for lowering blood glucose in patients with DM, and is believed to possess cardiovascular protective effects. The aim of this study was to investigate whether liraglutide has a protective effect on blood vessels and alleviates vascular intimal hyperplasia in streptozotocin (STZ)-induced rabbits with DM and its molecular mechanism. Methods: Rabbits with DM were induced by STZ, and a lower limb ischemia model was established. The animals were divided into a control group, DM-injury group and liraglutide treatment group. Pathological staining was used to observe the intimal growth, analyze the oxidation levels of malondialdehyde (MDA), superoxide dismutase (SOD) and plasma glutathione peroxidase (GSH-Px), and analyze the changes in expression of marker proteins and signaling pathway proteins by Western blotting. A hyperglycemia (HG)-injured vascular smooth muscle cells (VSMCs) model was established to analyze reactive oxygen species (ROS) levels, Cell-Counting Kit-8 (CCK-8) was used to analyze cell proliferation, scratch assay and Transwell Migration Assay to analyze cell migration, flow cytometry to analyze apoptosis and Western blotting was used to analyze changes in the expression of marker and signaling pathway proteins. Results: The results of pathological staining showed that intimal hyperplasia was severe after diabetes-induced lower limb ischemia in rabbits at 4 weeks, and liraglutide treatment reduced symptoms. Liraglutide treatment significantly decreased MDA content, increased SOD, GSH-Px content, and augmented total antioxidant capacity levels in tissues. The results of Western blotting analysis showed that E-cadherin, mitochondrial membrane potential 9 (MMP-9), proliferating cell nuclear antigen (PCNA), and type I collagen protein expression levels were significantly decreased after liraglutide treatment compared with the DM injury group. The results indicated that liraglutide inhibited epithelial-mesenchymal transition (EMT) progression, vascular cell proliferation and migration and collagen production. Liraglutide inhibits transforming growth factor beta 1 (TGF-ß1)/Smad3 signaling pathway protein expression. In vitro assays have shown that liraglutide reduces cellular ROS levels, inhibits cell proliferation and migration and promotes apoptosis. Liraglutide down-regulated the expression of E-cadherin, MMP-9, PCNA, type I collagen protein as well as the TGF-ß1/Smad3 signaling pathway, but this effect could be reversed by tumor necrosis factor alpha (TNF-α). Conclusion: Liraglutide can significantly improve tissue antioxidant capacity, reduce vascular cell proliferation and migration via the TGF-ß1/Smad3 signaling pathway, inhibit the EMT and collagen production processes, and alleviate hyperglycemia(HG)-induced lower limb ischemia and intimal hyperplasia.

Research on Bayer Red Mud Slurry Electrolysis.

The Bayer red mud is the solid waste generated during the production of alumina by the Bayer process. At present, the stock of red mud in China exceeds 1.1 billion tons, covering an area of more than 120,000 mu, and the annual production volume is increasing by 100 million tons. The comprehensive utilization of red mud is still a difficult problem. Therefore, it is of great significance to actively explore new methods for removing sodium from red mud. In this study, the traditional red mud desalination process and the slurry electrolysis process are combined, and the influence of three different leaching agents on the leaching and sodium removal of red mud slurry in the presence of an electric field is explored. In the slurry electrolysis experiment, it was found that the sodium removal rate obtained by different leaching agents was CaO > CaCl2 > HCl. The red mud leached with pure dilute hydrochloric acid has the highest Na removal rate, which is 93.11%. In view of this situation, a pre-slurry-electrolysis cycle process with HCl as leaching agent was proposed. The core of slurry electrolysis is electrolyzing NaCl solution, and HCl only participates in the process as circulating medium. The design of this process reduces cost and increases efficiency.

Research on the mechanism of sodium separation in bauxite residue synergy preparation of potassium-containing compound fertilizer raw materials by the hydrothermal method.

Bauxite residue poses an increasingly serious ecological safety problem in the alumina industry. A novel process for removing sodium in bauxite residue synergistic preparation of potassium-containing compound fertilizer raw materials was proposed to relieve pressure on the fertilizer industry. In this paper, synthetic sodalite and katoite were used to simulate the main mineral phases of bauxite residue to determine the suitable conditions for the method, and the transformation mechanism of the process was researched by analyzing the phase structure and microscopic morphology of the samples using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and specific surface area detection. The results show that the ideal reaction condition is 320 g/L K2O with solid reactants at 200 °C for 1 h. The separation rate of Na in the sodalite-katoite mixture reached 93.60%, with potassium aluminum silicate and katoite being the primary phases of the product, with a mesoporous structure and easy to be absorbed by crops. The bauxite residue transformation residue consisted of katoite and kaliophilite. With a total effective K2O, CaO, and SiO2 content of 38.22%, the Na2O content was 0.54%, meeting the requirements of compound fertilizer content on the market. The transformation mechanism is a dissolution-precipitation controlled sodium-potassium ion replacement reaction. This study provides theoretical guidance for the preparation of mineral fertilizer from bauxite residue and has practical production potential, opening up a new perspective for bauxite residue resource usage in the agricultural field.

Study on Iron Extraction from High Iron Bauxite Residue by Pyrite Reduction.

A new method of solid-phase reduction magnetic separation with pyrite as a reducing agent was proposed in order to realize resource utilization of high iron bauxite residue while reducing environmental harm. FeS2 powder and high iron bauxite residue powder were uniformly blended and roasted in a closed environment. A magnetic separator was utilized to separate the magnetic iron concentrate at 2400 GS, and the recovery rates were calculated. Experimental results show that the best iron recovery was 91.5% at 1:6 roasted bauxite: residue at 800℃ for 2 h. The recovery of Fe can be improved by reducing high iron bauxite residue with pyrite, and iron in both pyrite and high iron bauxite residue can be recovered simultaneously, alleviating the pressure of iron ore resources and improving its utilization value.

Comprehensive Application Technology of Bauxite Residue Treatment in the Ecological Environment: A Review.

The emission of bauxite residue continues to grow with the increase of alumina production capacity, along with the large amounts of bauxite residue currently stored in stockpiles. The exposed problems of high yield, strong alkalinity, low comprehensive utilization rate, and threats to the ecological environment are becoming increasingly prominent. With the strict requirements of environmental protection, improving the comprehensive utilization rate of bauxite residue and bulk consumption of bauxite residue has become an urgent issue to be solved. A large number of researchers have conducted in-depth investigations into the application of bauxite residue over a wide range, and this paper summarizes its application in the environment in recent years, providing guidance for the high value and harmless application of bauxite residue, which can help reduce environmental pollution and human life and health hazards caused by bauxite residue.

[Optimization of extraction of flavonoids from Lonicera rupicola and analysis of its effects in resisting inflammation, relieving pain, enhancing immunity, and inhibiting pyroptosis].

The present study optimized the extraction of flavonoids from Lonicera rupicola Hook. f. et Thoms(LRH) and explored its pharmacological effects, such as resisting inflammation, relieving pain, enhancing immunity, and inhibiting pyroptosis, aiming to provide data support and scientific basis for the development and utilization of LRH. Response surface methodology(RSM) was applied to optimize the extraction of flavonoids from LRH based on the results of single-factor experiments. Anti-inflammatory and analgesic effects of LRH flavonoids were evaluated via inflammation and pain models in mice, such as xylene-induced ear swelling, carrageenan-induced footpad swelling, writhing caused by acetic acid, and paw licking. The effect of LRH flavonoids on the carbon clearance index of monocytes and serum immunoglobulin A(IgA) and IgM levels was analyzed on the immunosuppression model induced by cyclophosphamide in mice. The anti-oxidative effect in vivo of LRH flavonoids on liver superoxide dismutase(SOD), catalase(CAT), and malondialdehyde(MDA) levels was determined based on the chronic/subacute aging model in mice induced by D-galactose. The levels of cysteinyl aspartate specific proteinase-1(caspase-1), interleukin-1ß(IL-1ß), and IL-18 in the supernatant of J774 A.1 mononuclear phagocytes were detected to evaluate the effect of LRH flavonoids on the pyroptosis of mononuclear phagocytes in mice induced by the combination of lipopolysaccharide(LPS) and adenosine triphosphate(ATP). Meanwhile, the effect of LRH flavonoids on the cAMP-PKA signaling pathway was also explored. The optimum conditions for the extraction of LRH flavonoids are listed below: extraction temperature of 65 ℃, the ethanol concentration of 50%, extraction time of 60 min, a material-liquid ratio at 1∶25, and the yield of LRH flavonoids of 0.553%. RSM determined the multiple quadratic regression equation model of response value and variables as follows: the yield of LRH flavonoids=0.61-0.48A+0.1B+0.029C-0.014D+0.32AB+0.04AC-0.012AD-0.02BC+0.037BD-0.031CD-0.058A~2-0.068B~2-0.069C~2-0.057D~2. LRH flavonoids could effectively inhibit ear swelling and footpad swelling, reduced acetic acid-induced writhing, and delayed the paw licking response time in mice. Additionally, LRH flavonoids could improve the carbon clearance index in immunosuppressed mice, potentiate the activities of SOD and CAT and reduce MDA levels in the liver of aging mice induced by D-galactose, and effectively inhibit macrophage pyroptosis by decreasing the levels of caspase-1, IL-1ß, and IL-18. The results reveal that LRH flavonoids possess excellent pharmacological activities such as resisting inflammation and oxidation, relieving pain, and enhancing immunity. They can inhibit pyroptosis by enhancing the cAMP-PKA signaling pathway. The results of this study can underpin the pharmacological research, development, and utilization of LRH.

Dibenzocyclooctadiene lignans from Artemisia sieversiana and their anti-inflammatory activities.

Two previously undescribed dibenzocyclooctadiene lignans, named sieverlignans D-E (1-2), as well as eight known ones (3-10), were isolated from the aerial parts of Artemisia sieversiana. Their structures were elucidated from extensive spectroscopic analysis, including HRMS, NMR and electronic circular dichroism (ECD) experiments. This study is the first to report dibenzocyclooctadiene lignans in the genus Artemisia and this plant. All the compounds were evaluated for their anti-neuroinflammatory activities on the lipopolysaccharides (LPS)-induced nitric oxide production in BV-2 murine microglial cells. Compounds 1 and 6 exhibited the moderate activities with their IC50 values of 47.7 and 21.9 µM, compared to a positive control quercetin with the IC50 value of 16.0 µM.

Optimization of extraction of flavonoids from Lonicera rupicola and analysis of its effects in resisting inflammation, relieving pain, enhancing immunity, and inhibiting pyroptosis / 中国中药杂志

The present study optimized the extraction of flavonoids from Lonicera rupicola Hook. f. et Thoms(LRH) and explored its pharmacological effects, such as resisting inflammation, relieving pain, enhancing immunity, and inhibiting pyroptosis, aiming to provide data support and scientific basis for the development and utilization of LRH. Response surface methodology(RSM) was applied to optimize the extraction of flavonoids from LRH based on the results of single-factor experiments. Anti-inflammatory and analgesic effects of LRH flavonoids were evaluated via inflammation and pain models in mice, such as xylene-induced ear swelling, carrageenan-induced footpad swelling, writhing caused by acetic acid, and paw licking. The effect of LRH flavonoids on the carbon clearance index of monocytes and serum immunoglobulin A(IgA) and IgM levels was analyzed on the immunosuppression model induced by cyclophosphamide in mice. The anti-oxidative effect in vivo of LRH flavonoids on liver superoxide dismutase(SOD), catalase(CAT), and malondialdehyde(MDA) levels was determined based on the chronic/subacute aging model in mice induced by D-galactose. The levels of cysteinyl aspartate specific proteinase-1(caspase-1), interleukin-1β(IL-1β), and IL-18 in the supernatant of J774 A.1 mononuclear phagocytes were detected to evaluate the effect of LRH flavonoids on the pyroptosis of mononuclear phagocytes in mice induced by the combination of lipopolysaccharide(LPS) and adenosine triphosphate(ATP). Meanwhile, the effect of LRH flavonoids on the cAMP-PKA signaling pathway was also explored. The optimum conditions for the extraction of LRH flavonoids are listed below: extraction temperature of 65 ℃, the ethanol concentration of 50%, extraction time of 60 min, a material-liquid ratio at 1∶25, and the yield of LRH flavonoids of 0.553%. RSM determined the multiple quadratic regression equation model of response value and variables as follows: the yield of LRH flavonoids=0.61-0.48A+0.1B+0.029C-0.014D+0.32AB+0.04AC-0.012AD-0.02BC+0.037BD-0.031CD-0.058A~2-0.068B~2-0.069C~2-0.057D~2. LRH flavonoids could effectively inhibit ear swelling and footpad swelling, reduced acetic acid-induced writhing, and delayed the paw licking response time in mice. Additionally, LRH flavonoids could improve the carbon clearance index in immunosuppressed mice, potentiate the activities of SOD and CAT and reduce MDA levels in the liver of aging mice induced by D-galactose, and effectively inhibit macrophage pyroptosis by decreasing the levels of caspase-1, IL-1β, and IL-18. The results reveal that LRH flavonoids possess excellent pharmacological activities such as resisting inflammation and oxidation, relieving pain, and enhancing immunity. They can inhibit pyroptosis by enhancing the cAMP-PKA signaling pathway. The results of this study can underpin the pharmacological research, development, and utilization of LRH.

A new strategy for the preparation of antibody against natural glycoside: With astragaloside IV as an example.

A new strategy for the hapten design of natural glycoside and application for the preparation of antibody is reported in this work. With astragaloside IV (AGS-IV) as an example, C6"-CH2OH on a glucosyl group was selectively oxidized by 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) oxidation to C6"-COOH, which was subsequently condensed with -NH2 on bovine serum albumin to get artificial antigen. Then, the successful preparation of artificial antigen was verified by TCL, SDS-PAGE, UV, and MALDI-TOF-MS. Finally, rabbits were immunized with artificial antigen to obtain an antibody against AGS-IV. After tests of the titer, IC50, and cross-reactivity, the results showed that the antibody prepared by TEMPO oxidation in this work had higher specificity than that the antibody prepared by conventional sodium periodate (NaIO4) oxidation. The hapten, as a carboxylic acid derivative of AGS-IV, has better water solubility than AGS IV, which is more suitable for the synthesis of the hapten-carrier protein conjugate in aqueous phase, achieving another virtue of TEMPO oxidation over NaIO4 oxidation. This new strategy provides new ideas for the design of haptens of other natural glycosides, as well as the preparation of their antibodies.