Preparation and interface state of phosphate tailing-based geopolymers

The long-term storage of phosphate tailings will occupy a large amount of land,pollute soil and groundwater,thus,it is crucial to achieve the harmless disposal of phosphate tailings.In this study,high-performance geopolymers with compressive strength of 38.8 MPa were prepared by using phosphate tailings as the main raw material,fly ash as the active silicon-aluminum material,and water glass as the alkaline activator.The solid content of phosphate tailings and fly ash was 60% and 40%,respectively,and the water-cement ratio was 0.22.The results of XRD,FTIR,SEM-EDS and XPS show that the reactivity of phosphate tailings with alkaline activator is weak,and the silicon-aluminum material can react with alkaline activator to form zeolite and gel,and encapsulate/cover the phosphate tailings to form a dense phosphate tailings-based geopolymer.During the formation of geopolymers,part of the aluminum-oxygen tetrahedron replaced the silicon-oxygen tetrahedron,causing the polycondensation reaction between geopolymers and increasing the strength of geopolymers.The leaching toxicity test results show that the geopolymer has a good solid sealing effect on heavy metal ions.The preparation of geopolymer from phosphate tailings is an important way to alleviate the storage pressure and realize the resource utilization of phosphate tailings.

浅析马钱子中毒

我院近年来,接治了因误食含有马钱子的中药过量而中毒的动物多例,对该中毒病的中毒机理、中毒症状和中毒的救治有了一定的认识,浅析如下,以供同行参考.

Screening of Toxin Mutant of Dickeya zeae and Its Biological Characters

[Objective]This study aimed to screen toxin mutant of Dickeya zeae(Erwinia chrysanthemi pv.zeae)and investigate its biological characters.[Method]We obtained a toxin mutant strain D.zeae Ech7-3-42 by using acridine orange as a mutagenic agent and compared their biological characteristics and virulence between the toxin mutant and wild strain.[Result]There was no significant difference in pectin lyase,protease,cellulase and the production of extracellular polysaccharide and lipopolysaccharide,but significant difference in toxin biological activities and virulence.Ech7-3-42 mutant did not produce toxin,as well as the loss of virulence on rice and HR on tobacco,but did not lose the ability to soft rot on potato.Mutant strain Ech7-3-42 can infect rice root and then enriched in the root neck and stalk,but it could not cause rice foot rot.Dickeya zeae(wild and mutant strain)could be detected by PCR in the root neck and below the 1-2 cm long stem area,but could not be detected in the leaves.[Conclusion]We believed that toxin may be one of the important factors for D.zeae virulence on rice.

Network pharmacology and molecular docking analysis on molecular targets and mechanism prediction of Huanglian Jiedu Decoction in the treatment of COVID-19

Objective To investigate and predict the molecular targets and mechanism of Huanglian Jiedu Decoction(黄连解毒汤,HLJDD)in the treatment of Corona Virus Disease 2019(COV-ID-19)through network pharmacology and molecular docking analysis.Methods The chemical constituents and action targets of HLJDD were retrieved on Tradi-tional Chinese Medicine Systems Pharmacology Database and Analysis Platform(TCMSP),SymMap v2,Encyclopedia of Traditional Chinese Medicine(ETCM),a High-throughput Ex-periment-and Reference-guided Database of Traditional Chinese Medicine(HERB),and Tra-ditional Chinese Medicine Integrated Database(TCMID).UniProt and GeneCards were used to query the target genes that corresponding to the active compounds,and then a compound-target network was constructed using Cytoscape 3.7.2.Gene Ontology(GO)database was used to annotate GO functions.Kyoto Encyclopedia of Genes and Genomes(KEGG)was used to predict the possible mechanisms of active compounds.The Database for Annotation,Visu-alization and Integrated Discovery(DAVID)was used to analysis the tissue enrichment.The main active compounds in HLJDD are molecularly docked with their corresponding related targets.Results Seventy-six compounds were screened and 458 corresponding targets in the network were obtained.Gene annotation showed that the targets were involved mainly in 1953 biolo-gical processes.884 signaling pathways was enriched,involving signaling by interleukins,cy-tokine signaling in immune system,generic transcription pathway,and RNA polymerase II transcription.The targets mainly distributed in the lung,liver,and placenta,involving a vari-ety of immune cells,such as T cells and B cells.The molecular docking results showed that core compounds such as wogonin,berberine,and baicalein had high affinity with tumor nec-rosis factor(TNF),insulin(INS),and tumor protein 53(TP53).Conclusion The active compounds in HLJDD may have a therapeutic effect on COVID-19 through regulating multiple signal pathways by targeting genes such as vascular endothelial growth factor A(VEGFA),INS,interleukin-6(IL-6),TNF,caspase-3,TP53,and mitogen-activ-ated protein kinase 3(MAPK3).