13 results on '"Xu-Sheng Liu"'
Search Results
2. Microstructural evolution of Cu/W nano-multilayers filler metal during thermal treatment
- Author
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Hong Li, Zeng-cheng Xing, Bo-jin Li, Xu-sheng Liu, Benjamin Lehmert, Manka Matthias, Zhuo-xin Li, and Wolfgang Tillmann
- Subjects
Condensed Matter Physics ,Instrumentation ,Surfaces, Coatings and Films - Published
- 2022
3. 20-Hydroxyecdysone promotes release of GBP-binding protein from oenocytoids to suppress hemocytic encapsulation
- Author
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Jia-Lin Wang, Xiao-Qiang Yu, Ke Liu, Gui-Jie Wang, Yu-Feng Wang, Xiao-Rong Zhuo, Xu-Sheng Liu, and Lei Chen
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0106 biological sciences ,0301 basic medicine ,Hemocytes ,Lysis ,medicine.medical_treatment ,20-Hydroxyecdysone ,Peptide ,Moths ,Helicoverpa armigera ,01 natural sciences ,Biochemistry ,03 medical and health sciences ,chemistry.chemical_compound ,Hemolymph ,medicine ,Animals ,Amino Acid Sequence ,Molecular Biology ,Peptide sequence ,chemistry.chemical_classification ,biology ,Binding protein ,biology.organism_classification ,010602 entomology ,Ecdysterone ,030104 developmental biology ,Cytokine ,chemistry ,Larva ,Insect Science ,Cytokines ,Insect Proteins ,Sequence Alignment - Abstract
Growth-blocking peptide (GBP) is an insect cytokine that stimulates plasmatocyte adhesion, thereby playing a critical role in encapsulation reaction. It has been previously demonstrated that GBP-binding protein (GBPB) is released upon oenocytoid lysis in response to GBP and is responsible for subsequent clearance of GBP from hemolymph. However, current knowledge about GBPB is limited and the mechanism by which insects increase GBPB levels to inactivate GBP remains largely unexplored. Here, we have identified one GBP precursor (HaGBP precursor) gene and two GBPB (namely HaGBPB1 and HaGBPB2) genes from the cotton bollworm, Helicoverpa armigera. The HaGBP precursor was found to be predominantly expressed in fat body, whereas HaGBPB1 and HaGBPB2 were mainly expressed in hemocytes. Immunological analyses indicated that both HaGBPB1 and HaGBPB2 are released from hemocytes into the plasma during the wandering stage. Additionally, 20-hydroxyecdysone (20E) treatment or bead challenge could promote the release of HaGBPB1 and HaGBPB2 at least partly from oenocytoids into the plasma. Furthermore, we demonstrate that the N-terminus of HaGBPB1 is responsible for binding to HaGBP and suppresses HaGBP-induced plasmatocyte spreading and encapsulation. Overall, this study helps to enrich our understanding of the molecular mechanism underlying 20E mediated regulation of plasmatocyte adhesion and encapsulation via GBP-GBPB interaction.
- Published
- 2018
4. Theoretical analysis on lead halides content dependences of defect structures and spin Hamiltonian parameters in lead halo borate glass composites with V2O5 dopants
- Author
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Xing-Yuan Yu, Gao-Qiang Shen, Shao-Yi Wu, Qin-Sheng Zhu, Xu-Sheng Liu, and Xiao-Yu Li
- Subjects
Materials science ,Dopant ,chemistry.chemical_element ,Borate glass ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Tetragonal crystal system ,symbols.namesake ,Fourier transform ,Octahedron ,chemistry ,Mechanics of Materials ,Ceramics and Composites ,symbols ,Ionic conductivity ,Composite material ,0210 nano-technology ,Polarization (electrochemistry) ,Boron - Abstract
The defect structures and spin Hamiltonian parameters (SHPs) for V4+ in lead halo borate (xPbX2–(30 − x)PbO–68B2O3, X = F, Cl, Br and x = 5, 10, 15, 20 and 25 mol%) glass composites containing 2 mol% of V2O5 dopant are theoretically studied by applying the perturbation formulas of the SHPs for tetragonally compressed octahedral 3d1 clusters. The experimental SHPs are suitably reproduced by the optimal covalency factor N, relative tetragonal compression ratio ρ, core polarization constant κ and reduction factor H at various x, which are simulated with the corresponding Fourier type content functions. The distinct deviations of these quantities from the relevant simulated Fourier type content functions at 5 mol% of PbCl2 and PbBr2 are reasonably explained from the modifications of compactness and electronic cloud redistributions around V4+ at this content. This is supported by the previous analysis on the content variations of ionic conductivity of the systems.
- Published
- 2021
5. Theoretical studies of the defect structures for the two Cr 3+ centers in KCl
- Author
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Jia-Xing Guo, Li-Juan Zhang, Hui-Ning Dong, Li-Na Wu, Shao-Yi Wu, and Xu-Sheng Liu
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Physics ,Ligand ,Doping ,Spin hamiltonian ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Electrostatics ,01 natural sciences ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,k-nearest neighbors algorithm ,Ion ,Crystallography ,Nuclear magnetic resonance ,Octahedron ,Impurity ,Electrical and Electronic Engineering ,0210 nano-technology - Abstract
The spin Hamiltonian (SH) parameters (i.e. the zero-field splitting parameters (ZFSPs) and g factors) and local structures of the two Cr3+ centers I and II at room temperature in KCl single crystals are theoretically investigated from the perturbation calculations for a rhombically distorted octahedral 3d3 cluster. The impurity systems are attributed to the doped Cr(CN)63− groups into KCl replacing the host KCl65− ones, associated with two nearest neighbor potassium vacancies VK in [011] and [ 0 1 ¯ 1 ¯ ] axes in center I and one nearest neighbor VK along [ 0 1 ¯ 1 ] and another next-nearest neighbor VK along [100] axis in center II, respectively. In center I, the four coplanar and two axial ligands CN− undergo the shifts ∆R1 (≈0.0044 nm) away from the VK and ∆R2′ (≈0.0144 nm) away from the central ion along Z axis, respectively, because of the electrostatic interactions. In center II, the impurity Cr3+ is found to undergo the shift ∆RC (≈0.0063 nm) towards the nearest neighbor VK along [ 0 1 ¯ 1 ] axis, while the two ligands in [001] and [ 0 1 ¯ 0 ] axes closest to the VK undergo the shifts ∆R1 (≈0.0081 nm) away from the respective VK, and the ligand intervening in the VK and the central ion experiences the shift ∆R2 (≈0.0238 nm) away from the VK along [100] axis. The charge-transfer (CT) contributions to g-shifts are found to be opposite in sign and more than half (characterized by the ratios |ΔgCT/ΔgCF|>50%) in magnitude compared with the CF ones for both centers. The local structures and the microscopic mechanisms of the relevant impurity and ligand shifts are discussed for the two centers.
- Published
- 2017
6. Investigations of the spin Hamiltonian parameters and local structures for Fe3+, Cr3+ and Mn4+ in rutile TiO2 single crystal
- Author
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Hui-Ning Dong, Xu-Sheng Liu, and Hong-Fei Zhou
- Subjects
Physics ,Condensed Matter Physics ,Molecular physics ,Electronic, Optical and Magnetic Materials ,law.invention ,Nuclear magnetic resonance ,Molecular geometry ,Octahedron ,law ,Rutile ,Impurity ,Perpendicular ,Electrical and Electronic Engineering ,Electron paramagnetic resonance ,Hyperfine structure ,Single crystal - Abstract
The spin Hamiltonian parameters ( g factors, hyperfine structure constants and zero-field splittings (ZFSs)) and local structures for the rhombic substitutional Fe 3+ , Cr 3+ and Mn 4+ in rutile (TiO 2 ) single crystal are theoretically investigated from the high order perturbation calculations based on the cluster approach including both the crystal-field (CF) and charge-transfer (CT) contributions to the g factors and hyperfine structure constants. The impurity centers are found to undergo the local axial distortions Δ Z (≈0.22, 0.14 and –0.18 Ǻ) and the planar bond angle variations Δ φ (≈4.3, 5.9 and 0.2°) for Fe 3+ , Cr 3+ and Mn 4+ , respectively. The signs for ZFSs D and E are analyzed in the light of those for Δ Z and rhombic distortion angle δ φ (= φ′ – π /4) related to an ideal octahedron. The magnitudes of Δ Z and Δ φ are conveniently illustrated by the axial and perpendicular ZFS relative variations Δ F and Δ G for the deviations of D and E based on the local distortion parameters from those ( D H and E H ) based on the host structural data of Ti 4+ site. The validity of the above local structures is discussed in view of size and charge mismatch of the various impurity centers. The CT contributions to g-shift are opposite in sign and about 13–56% in magnitude compared with the CF ones, indicating the increasing importance (Cr 3+ 3+ 4+ ). The CT contributions to hyperfine structure constants are the same in sign and about 19–22% in magnitude with respect to the corresponding CF contributions.
- Published
- 2015
7. Theoretical investigations on the defect structures and g factors for W5+ in lead bismuth arsenate glasses
- Author
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Ying-Jie Luo, Xu-Sheng Liu, Si-Ling Yue, Meng Han, Qing-Sheng Zhu, and Shao-Yi Wu
- Subjects
Materials science ,Niobium ,chemistry.chemical_element ,02 engineering and technology ,01 natural sciences ,law.invention ,chemistry.chemical_compound ,symbols.namesake ,law ,0103 physical sciences ,Materials Chemistry ,Boron ,Electron paramagnetic resonance ,Lead bismuth ,010302 applied physics ,Arsenate ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Alkali metal ,Electronic, Optical and Magnetic Materials ,Fourier transform ,Octahedron ,chemistry ,Ceramics and Composites ,symbols ,Physical chemistry ,0210 nano-technology - Abstract
Electron paramagnetic resonance (EPR) g factors and defect structures for W5+ in alkali niobium borate glasses (40–x)PbO-15Bi2O3-45As2O3-xWO3 (PBA, x = 1–6 mol%) are theoretically investigated from the g formulas for tetragonally compressed octahedral 5d1 clusters. The d-d transition bands (including the minimal at 4 mol%) for varying concentrations are satisfactorily reproduced from the Fourier type function of x. The concentration dependences of g factors are reasonably explained from the parabolic functions for covalency factor N (
- Published
- 2020
8. Rab3 is involved in cellular immune responses of the cotton bollworm, Helicoverpa armigera
- Author
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Xu-Sheng Liu, Jia-Lin Wang, Yu-Ping Li, Li Li, Xiu-Hong Wei, Jie Li, and Cai-Xia Song
- Subjects
Hemocytes ,rab3 GTP-Binding Proteins ,Phagocytosis ,Molecular Sequence Data ,Immunology ,Moths ,Biology ,Helicoverpa armigera ,medicine.disease_cause ,Immune system ,Hemolymph ,Botany ,Escherichia coli ,medicine ,Animals ,Amino Acid Sequence ,RNA, Small Interfering ,Immunity, Cellular ,Gene knockdown ,Innate immune system ,Base Sequence ,DEAE-Dextran ,fungi ,Sequence Analysis, DNA ,biology.organism_classification ,Bacterial Load ,Immunity, Innate ,Microspheres ,Recombinant Proteins ,Cell biology ,Larva ,RNA Interference ,Rab ,Developmental Biology - Abstract
Rab3, a member of the Rab GTPase family, has been found to be involved in innate immunity. However, the precise function of this GTPase in innate immunity remains unknown. In this study, we identified a Rab3 gene (Ha-Rab3) from the cotton bollworm, Helicoverpa armigera and studied its roles in innate immune responses. Expression of Ha-Rab3 was upregulated in the hemocytes of H. armigera larvae after the injection of Escherichia coli or chromatography beads. The dsRNA-mediated knockdown of Ha-Rab3 gene in H. armigera larval hemocytes led to significant reduction in the phagocytosis and nodulation activities of hemocytes against E. coli, significant increase in the bacterial load in larval hemolymph, and significant reduction in the encapsulation activities of hemocytes toward invading chromatography beads. Furthermore, Ha-Rab3 knockdown significantly suppressed spreading of plasmatocytes. These results suggest that Ha-Rab3 plays important roles in H. armigera cellular immune responses, possibly by mediating spreading of hemocytes.
- Published
- 2015
9. WITHDRAWN: C-type lectin interacting with β-integrin enhances hemocytic encapsulation in the cotton bollworm, Helicoverpa armigera
- Author
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Pan Wang, Jia-Lin Wang, Xiao-Rong Zhuo, Xu-Sheng Liu, Xiao-Qiang Yu, Yu-Feng Wang, Lin Tang, and Guo-Xiu Wang
- Subjects
0301 basic medicine ,Gene knockdown ,biology ,Pattern recognition receptor ,20-Hydroxyecdysone ,Helicoverpa armigera ,biology.organism_classification ,Biochemistry ,In vitro ,Cell biology ,03 medical and health sciences ,chemistry.chemical_compound ,030104 developmental biology ,chemistry ,C-type lectin ,Insect Science ,Botany ,Receptor ,Molecular Biology ,Ecdysone - Abstract
The encapsulation reaction in invertebrates is analogous to granuloma formation in vertebrates, and this reaction is severely compromised when ecdysone signaling is blocked. However, the molecular mechanism underlying the encapsulation reaction and its regulation by ecdysone remains obscure. In our previous study, we found that the C-type lectin HaCTL3, from the cotton bollworm Helicoverpa armigera, is involved in anti-bacterial immune response, acting as a pattern recognition receptor (PRR). In the current study, we demonstrate that HaCTL3 is involved in defense against parasites and directly binds to the surface of nematodes. Our in vitro and in vivo studies indicate that HaCTL3 enhances hemocytic encapsulation and melanization, whereas H. armigera β-integrin (Haβ-integrin), located on the surface of hemocytes, participates in encapsulation. Additionally, co-immunoprecipitation experiments reveal HaCTL3 interacts with Haβ-integrin, and knockdown of Haβ-integrin leads to reduced encapsulation of HaCTL3-coated beads. These results indicate that Haβ-integrin serves as a hemocytic receptor of HaCTL3 during the encapsulation reaction. Furthermore, we demonstrate that 20-hydroxyecdysone (20E) treatment dramatically induces the expression of HaCTL3, and knockdown of the 20E receptor (EcR)/ultraspiracle (USP), abrogates this response. Overall, this study provides the first evidence of the presence of a hemocytic receptor (Haβ-integrin), that interacts with the PRR HaCTL3 to facilitate encapsulation reaction in insects and demonstrates the regulation of this process by the steroid hormone ecdysone.
- Published
- 2017
10. Involvement of a pattern recognition receptor C-type lectin 7 in enhancing cellular encapsulation and melanization due to its carboxyl-terminal CRD domain in the cotton bollworm, Helicoverpa armigera
- Author
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Lin Tang, Qi Zhang, Yu-Feng Wang, Xu-Sheng Liu, Lei Chen, and Jia-Lin Wang
- Subjects
Agglutination ,Hemocytes ,Immunology ,Helicoverpa armigera ,Gram-Positive Bacteria ,law.invention ,C-type lectin ,law ,Gram-Negative Bacteria ,Animals ,Lectins, C-Type ,Transgenes ,Cloning, Molecular ,Cells, Cultured ,Melanins ,Innate immune system ,biology ,Pattern recognition receptor ,Lectin ,biology.organism_classification ,Immunity, Innate ,Protein Structure, Tertiary ,Cell biology ,Lepidoptera ,Receptors, Pattern Recognition ,Recombinant DNA ,biology.protein ,Insect Proteins ,Calcium ,Bacteria ,Protein Binding ,Developmental Biology ,Cysteine - Abstract
C-type lectins play important roles in innate immunity as pattern recognition receptors (PRRs). We have previously reported a novel C-type lectin HaCTL7 from the cotton bollworm (Helicoverpa armigera) which contains two carbohydrate-recognition domains (CRDs), namely N-terminal CRD1 and C-terminal CRD2. Interestingly, there are four but not six of conserved cysteine residues in CRD2 of HaCTL7, which is different from that of other dual CRD C-type lectins. In the current study, we expressed and purified recombinant HaCTL7 (rHaCTL7) as well as rCRD1 and rCRD2, and demonstrated that both rHaCTL7 and rCRD2, but not rCRD1, owned the agglutinate ability against both Gram-negative and Gram-positive bacteria in a calcium dependent manner. In addition, both rHaCTL7 and rCRD2, but not rCRD1, could bind to various bacteria, and enhanced haemocytes mediated encapsulation and melanization processes. HaCTL7 secreted from fat bodies is able to bind to granulocytes, plasmatocytes and oenocytoids, but not to spherulocytes. Recombinant HaCTL7 and rCRD2 are capable of binding to both granulocytes and oenocytoids, while rCRD1 can only bind to granulocytes. Our data suggest that as a PRR HaCTL7 enhances encapsulation and melanization likely through its C-terminal CRD2, but not N-terminal CRD1, which imply that the characteristic four cysteine structure of CRD2 plays key roles in innate immunity.
- Published
- 2014
11. SRP gene is required for Helicoverpa armigera prophenoloxidase activation and nodulation response
- Author
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Xu-Sheng Liu, Yu-Feng Wang, Chuan Qiao, Jia-Lin Wang, Jie Li, and Xiu-Hong Wei
- Subjects
Hemocytes ,Receptors, Peptide ,Immunology ,Receptors, Cytoplasmic and Nuclear ,Spodoptera litura ,Helicoverpa armigera ,medicine.disease_cause ,environment and public health ,Microbiology ,RNA interference ,Hemolymph ,Escherichia coli ,Hyphantria ,medicine ,Animals ,RNA, Small Interfering ,Escherichia coli Infections ,Enzyme Precursors ,Immunity, Cellular ,Innate immune system ,biology ,fungi ,Prophenoloxidase ,biology.organism_classification ,Virology ,Immunity, Innate ,Enzyme Activation ,Lepidoptera ,Gene Expression Regulation ,Catechol Oxidase ,Developmental Biology - Abstract
SRP gene was first identified from the fall webworm, Hyphantria cunea as one of genes up-regulated after bacteria injection. A rent study in Spodoptera litura showed that stress-induced elevation of SRP expression highly correlates with reduced feeding activities and growth retardation of larvae. In this study, we identified a SRP gene from the cotton bollworm, Helicoverpa armigera, namely Ha-SRP, and studied its precise roles in insect immunity. Expressions of Ha-SRP were upregulated in H. armigera larval hemocytes after injection of Escherichia coli. When the expression of Ha-SRP in H. armigera larval hemocytes was inhibited by dsHa-SRP injection, the transcription of prophenoloxidase genes in hemocytes was repressed, phenoloxidase activity in bacteria-challenged larval hemolymph was significantly decreased, and nodule formation in bacteria-injected larvae was reduced. More importantly, RNAi-treated insects infected with E. coli showed higher bacterial growth in hemolymph compared with infected controls. These results suggest that Ha-SRP gene plays importance roles in H. armigera innate immunity, possibly by mediating prophenoloxidase activation and nodulation response.
- Published
- 2014
12. Effects of limited interactions between individuals on cooperation in spatial evolutionary prisoner’s dilemma game
- Author
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Jian-Yue Guan, Xu-Sheng Liu, and Zhi-Xi Wu
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Dilemma ,Range (mathematics) ,Maximum level ,General Mathematics ,Applied Mathematics ,Stochastic game ,General Physics and Astronomy ,Statistical and Nonlinear Physics ,Function (mathematics) ,Prisoner's dilemma ,Mathematical economics ,Mathematics - Abstract
We study the spatial evolutionary prisoner's dilemma game with limited interactions by introducing two kinds of individuals, say type-A and type-B with a fraction of p and (1 - p), respectively, distributed randomly on a square lattice. Each kind of individuals can adopt two pure strategies: either to cooperate or to defect. During the evolution, the individuals can only interact with others belonging to the same kind, but they can learn from either kinds of individuals in the nearest neighborhood. Using Monte Carlo simulations, the average frequency of cooperators rho(c) is calculated as a function of p in the equilibrium state. It is shown that, compared with the case of p = 0 (only one kind of individuals existing in the system), cooperation can be evidently promoted. In particular, the cooperator density can reach a maximum level at some moderate values of p in a wide range of payoff parameters. The results imply that certain limited interactions between individuals plays an important and nontrivial role in the evolution of cooperation. (C) 2013 Elsevier Ltd. All rights reserved.
- Published
- 2013
13. Expression profiles of six novel C-type lectins in response to bacterial and 20E injection in the cotton bollworm (Helicoverpa armigera)
- Author
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Yu-Feng Wang, Hao-Bin Zhao, Qi Zhang, Xu-Sheng Liu, and Jia-Lin Wang
- Subjects
Signal peptide ,Fat Body ,Molecular Sequence Data ,Immunology ,Moths ,Helicoverpa armigera ,medicine.disease_cause ,law.invention ,Microbiology ,chemistry.chemical_compound ,law ,C-type lectin ,medicine ,Animals ,Lectins, C-Type ,Amino Acid Sequence ,Cloning, Molecular ,Receptor ,Escherichia coli ,Phylogeny ,Innate immune system ,biology ,Gene Expression Profiling ,fungi ,biology.organism_classification ,Virology ,chemistry ,Receptors, Pattern Recognition ,Recombinant DNA ,Insect Proteins ,Peptidoglycan ,Sequence Alignment ,Developmental Biology - Abstract
C-type lectins can act as pattern recognition receptors (PRRs) and play an important role in innate immunity. Two C-type lectins (HaCTL1 and HaCTL2) have been previously identified in the cotton bollworm (Helicoverpa armigera). Here we isolate six C-type lectins from H. armigera (HaCTL3, 4, 5, 6, 7 and 8). All six new HaCTLs encode a signal peptide (or partial signal peptide) and complete tandem carbohydrate-recognition domains (CRDs). HaCTL4, 5, 6, 7 and 8 mRNA increased in the fat body after injection with both killed Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus, whereas HaCTL3 mRNA was upregulated following E. coli injection only. Recombinant HaCTL3 exhibited agglutinating activity against both Gram-negative and Gram-positive bacteria in a calcium-dependent manner. Agglutination inhibitory analysis indicated that rHaCTL3 recognizes maltose, trehalose, peptidoglycan and lipopolysaccharides. HaCTL3 and HaCTL8 mRNA showed upregulation while HaCTL4, 5, and 6 mRNA downregulation post 20-Hydroxyecdysone (20E) injection. Our results indicate that the six novel C-type lectins of H. armigera may play important roles in defending against bacteria as PRRs and the hormone 20E can function in regulating immunity through lectins.
- Published
- 2012
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