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Topological edge and corner states of valley photonic crystals with zipper-like boundary conditions
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作者 沈云峰 许孝芳 +2 位作者 孙铭 周文佶 常雅箐 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第4期480-491,共12页
We present a stable valley photonic crystal(VPC)unit cell with C_(3v)symmetric quasi-ring-shaped dielectric columns and realize its topological phase transition by breaking mirror symmetry.Based on this unit cell stru... We present a stable valley photonic crystal(VPC)unit cell with C_(3v)symmetric quasi-ring-shaped dielectric columns and realize its topological phase transition by breaking mirror symmetry.Based on this unit cell structure,topological edge states(TESs)and topological corner states(TCSs)are realized.We obtain a new type of wave transmission mode based on photonic crystal zipper-like boundaries and apply it to a beam splitter assembled from rectangular photonic crystals(PCs).The constructed beam splitter structure is compact and possesses frequency separation functions.In addition,we construct a box-shaped triangular PC structures with zipper-like boundaries and discover phenomena of TCSs in the corners,comparing its corner states with those formed by other boundaries.Based on this,we explore the regularities of the electric field patterns of TESs and TCSs,explain the connection between the characteristic frequencies and locality of TCSs,which helps better control photons and ensures low power consumption of the system. 展开更多
关键词 valley photonic crystal topological edge states topological corner states higher-order topological insulators topological phase transition
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Mechanism of annexin A1/N-formylpeptide receptor regulation of macrophage function to inhibit hepatic stellate cell activation through Wnt/β-catenin pathway 被引量:1
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作者 Jun-Hua Fan Na Luo +3 位作者 Geng-Feng Liu xiao-fang xu Shi-Quan Li Xiao-Ping Lv 《World Journal of Gastroenterology》 SCIE CAS 2023年第22期3422-3439,共18页
BACKGROUND Hepatic fibrosis is a common pathological process of chronic liver diseases with various causes,which can progress to cirrhosis.AIM To evaluate the effect and mechanism of action annexin(Anx)A1 in liver fib... BACKGROUND Hepatic fibrosis is a common pathological process of chronic liver diseases with various causes,which can progress to cirrhosis.AIM To evaluate the effect and mechanism of action annexin(Anx)A1 in liver fibrosis and how this could be targeted therapeutically.METHODS CCl4(20%)and active N-terminal peptide of AnxA1(Ac2-26)and N-formylpeptide receptor antagonist N-Boc-Phe-Leu-Phe-Leu-Phe(Boc2)were injected intraperitoneally to induce liver fibrosis in eight wild-type mice/Anxa1 knockout mice,and to detect expression of inflammatory factors,collagen deposition,and the role of the Wnt/β-catenin pathway in hepatic fibrosis.RESULTS Compared with the control group,AnxA1,transforming growth factor(TGF)-β1,interleukin(IL)-1βand IL-6 expression in the liver of mice with hepatic fibrosis induced by CCl4 was significantly increased,which promoted collagen deposition and expression ofα-smooth muscle actin(α-SMA),collagen type I and connective tissue growth factor(CTGF),and increased progressively with time.CCl4 induced an increase in TGF-β1,IL-1βand IL-6 in liver tissue of AnxA1 knockout mice,and the degree of liver inflammation and fibrosis and expression ofα-SMA,collagen I and CTGF were significantly increased compared with in wild-type mice.After treatment with Ac2-26,expression of liver inflammatory factors,degree of collagen deposition and expression of a-SMA,collagen I and CTGF were decreased compared with before treatment.Boc2 inhibited the anti-inflammatory and antifibrotic effects of Ac2-26.AnxA1 downregulated expression of the Wnt/β-catenin pathway in CCl4-induced hepatic fibrosis.In vitro,lipopolysaccharide(LPS)induced hepatocyte and hepatic stellate cell(HSC)expression of AnxA1.Ac2-26 inhibited LPS-induced RAW264.7 cell activation and HSC proliferation,decreased expression ofα-SMA,collagen I and CTGF in HSCs,and inhibited expression of the Wnt/β-catenin pathway after HSC activation.These therapeutic effects were inhibited by Boc2.CONCLUSION AnxA1 inhibited liver fibrosis in mice,and its mechanism may be related to inhibition of HSC Wnt/β-catenin pathway activation by targeting formylpeptide receptors to regulate macrophage function. 展开更多
关键词 Annexin A1 Active N-terminal peptide of annexin A1 MACROPHAGE Hepatic stellate cell WNT/Β-CATENIN Liver fibro
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Bioleaching of two different types of chalcopyrite by Acidithiobacillus ferrooxidans 被引量:5
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作者 Ying-bo Dong Hai Lin +2 位作者 Kai-bin Fu xiao-fang xu Shan-shan Zhou 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2013年第2期119-124,共6页
Two different types of chalcopyrite (pyritic chalcopyrite and porphyry chalcopyrite) were bioleached with AcidithiobaciUus ferrooxidans ATF6. The bioleaching of the pyritic chalcopyrite and porphyry chalcopyrite is ... Two different types of chalcopyrite (pyritic chalcopyrite and porphyry chalcopyrite) were bioleached with AcidithiobaciUus 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. 展开更多
关键词 CHALCOPYRITE BIOLEACHING ADSORPTION functional groups
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Coupling relationship between multicomponent recovery of rare earth tailings 被引量:13
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作者 Yue Zhang Hai Lin +3 位作者 Ying-Bo Dong xiao-fang xu Xin Wang Yue-Jiao Gao 《Rare Metals》 SCIE EI CAS CSCD 2017年第3期220-228,共9页
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... 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 ana- lyzed; process flows and parameters which could give consideration to four kinds of components were deter- mined. 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 separa- tion, 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. 展开更多
关键词 Rare earth tailings RECOVERY Couplingrelationship
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A facile synthesis of cajaninstilbene acid and its derivatives
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作者 Qi Chen Kuo Lu +3 位作者 Chang Zheng xiao-fang xu Jing Lin Wei-Min Chen 《Chinese Chemical Letters》 SCIE CAS CSCD 2019年第8期1527-1529,共3页
A four-step synthesis of methyl 6-formyl-2-hydroxy-4-methoxy-3-(3-methylbut-2-en-1-yl)benzoate(11)that can be used as building block for a facile synthesis of cajaninstilbene acid and its derivatives is reported.The s... A four-step synthesis of methyl 6-formyl-2-hydroxy-4-methoxy-3-(3-methylbut-2-en-1-yl)benzoate(11)that can be used as building block for a facile synthesis of cajaninstilbene acid and its derivatives is reported.The synthesis of cajaninstilbene acid was accomplished in six steps with an overall yield of 20%starting from commercial materials by a synthesis whose key steps are TiCl4-mediated[3+3]cyclization and McMurry coupling. 展开更多
关键词 Cajaninstilbene ACID SYNTHESIS BUILDING BLOCK DERIVATIVES
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Local adaptive evolution of two distinct clades of Beijing and T families of Mycobacterium tuberculosis in Chongqing:a Bayesian population structure and phylogenetic study
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作者 Peng-Kuan Liang Chao Zheng +8 位作者 xiao-fang xu Zhe-Ze Zhao Chang-Song Zhao Chang-He Li David Couvin Yann Reynaud Thierry Zozio Nalin Rastogiand Qun Sun 《Infectious Diseases of Poverty》 SCIE 2020年第3期134-135,共2页
Background:Beijing sub-pedigree 2(BSP2)and T sub-lineage 6(TSL6)are two clades belonging to Beijing and T family of Mycobacterium tuberculosis(MTB),respectively,defined by Bayesian population structure analysis based ... Background:Beijing sub-pedigree 2(BSP2)and T sub-lineage 6(TSL6)are two clades belonging to Beijing and T family of Mycobacterium tuberculosis(MTB),respectively,defined by Bayesian population structure analysis based on 24-loci mycobacterial interspersed repetitive unit-variable number of tandem repeats(MIRU-VNTR).Globally,over 99%of BSP2 and 89%of TSL6 isolates were distributed in Chongqing,suggesting their possible local adaptive evolution.The objective of this paper is to explore whether BSP2 and TSL6 originated by their local adaptive evolution from the specific isolates of Beijing and T families in Chongqing.Methods:The genotyping data of 16090 MTB isolates were collected from laboratory collection,published literatures and SITVIT database before subjected to Bayesian population structure analysis based on 24-loci MIRUVNTR.Spacer Oligonucleotide Forest(Spoligoforest)and 24-loci MIRU-VNTR-based minimum spanning tree(MST)were used to explore their phylogenetic pathways,with Bayesian demographic analysis for exploring the recent demographic change of TSL6.Results:Phylogenetic analysis suggested that BSP2 and TSL6 in Chongqing may evolve from BSP4 and TSL5,respectively,which were locally predominant in Tibet and Jiangsu,respectively.Spoligoforest showed that Beijing and T families were genetically distant,while the convergence of the MIRU-VNTR pattern of BSP2 and TSL6 was revealed by WebLogo.The demographic analysis concluded that the recent demographic change of TSL6 might take 111.25 years.Conclusions:BSP2 and TSL6 clades might originate from BSP4 and TSL5,respectively,by their local adaptive evolution in Chongqing.Our study suggests MIRU-VNTR be combined with other robust markers for a more comprehensive genotyping approach,especially for families of clades with the same MIRU-VNTR pattern. 展开更多
关键词 Mycobacterium tuberculosis Local adaptive evolution MIRU-VNTR Bayesian population structure analysis Phylogenetic analysis
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