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Lattice and spin dynamics in multiferroic BiFeO3 and RMnO3

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National Science Review 2019年第4期6卷 642-652页

作者： Yan Song ben xu Ce-Wen Nan School of Materials Science and Engineering and State Key Laboratory of New Ceramics and Fine ProcessingTsinghua University

The multiferroic materials Bi Fe O3 and RMn O3 exhibit coexisting magnetic order and ferroelectricity, and provide exciting platforms for new physics and potentially novel devices, where intriguing interplay between phonons and magnons exists. In this review, we paint a complete picture of bulk BiFeO3together with orthorhombic and hexagonal RMnO3（R includes rare-earth elements and yttrium） by summarizing the dynamics of spin and lattice and their magnetoelectric coupling, as well as the methods of controlling these characteristics under non-equilibrium conditions, from experimental and simulation perspectives.

关键词： multiferroics phonon magnon

Towards a Unified Recurrent Neural Network Theory： The Uniformly Pseudo-Projection-Anti-Monotone Net

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Acta Mathematica Sinica,English Series 2011年第2期27卷 377-396页

作者： Zong ben xu Chen QIAO Institute for Information and System Science Faculty of Science MOE Key Lab for Intelligent Networks and Network Security Xi'an Jiaotong University Xi'an 710049 P. R. China qiaochen @mail.xjtu. edu. cn

In the past decades, various neural network models have been developed for modeling the behavior of human brain or performing problem-solving through simulating the behavior of human brain. The recurrent neural networks are the type of neural networks to model or simulate associative memory behavior of human being. A recurrent neural network （RNN） can be generally formalized as a dynamic system associated with two fundamental operators： one is the nonlinear activation operator deduced from the input-output properties of the involved neurons, and the other is the synaptic connections （a matrix） among the neurons. Through carefully examining properties of various activation functions used, we introduce a novel type of monotone operators, the uniformly pseudo-projectionanti-monotone （UPPAM） operators, to unify the various RNN models appeared in the literature. We develop a unified encoding and stability theory for the UPPAM network model when the time is discrete. The established model and theory not only unify but also jointly generalize the most known results of RNNs. The approach has lunched a visible step towards establishment of a unified mathematical theory of recurrent neural networks.

关键词： Feedback neural networks essential characteristics uniformly pseudo-projection-anti- monotone net unified theory dynamics

Dislocation-mediated migration of interphase boundaries

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Journal of Materials Science & Technology 2019年第11期35卷 2714-2726页

作者： Zhipeng Sun Fuzhi Dai ben xu Wenzheng Zhang School of Materials Science and Engineering Tsinghua UniversityBeijing 100084China Science and Technology of Advanced Functional Composite Laboratory Aerospace Research Institute of Materials and Processing TechnologyBeijing 100076China Key Laboratory of Advanced Materials(MOE) State Key Laboratory of New Ceramics and Fine ProcessingChina

Faceted interphase boundaries(IPBs)are commonly observed in lath-shaped precipitates in alloys consisting of simple face-centred cubic(fcc),body centred-cubic(bcc)or hexagonal closed packed(hcp)phases,which normally contain one or two sets of parallel *** influence of these dislocations on interface migration and possible accompanying long-range strain field remain *** elucidate this,we carried out atomistic simulations to investigate the dislocation-mediated migration processes of IPBs in a pure-iron *** results show that the migration of these IPBs is accompanied with the slip of interfacial dislocations,even in high-index slip planes,with two migration modes were observed:the first mode is the uniform migration mode that occurs only when all of the dislocations slip in a common slip plane.A shear-coupled interface migration was observed for this *** other interfaces propagate in the stick-slip migration mode that occurs when the dislocations glide on different slip planes,involving dislocation reaction or tangling.A quantitative relationship was established to link the atomic displacements with the dislocation structure,slip plane,and interface *** macroscopic shear deformation due to the effect of overall atomic displacement shows a good agreement with the results obtained based on the phenomenological theory of martensite *** findings have general implications for the understanding of phase transformations and the surface relief effect at the atomic scale.

关键词： Interphase boundary migration O-line interface Shear-coupled interface migration Dislocation gliding Atomic displacement

Curcumin Inhibits Proliferation of Renal Cell Carcinoma in vitro and in vivo by Regulating miR-148/ADAMTS18 through Suppressing Autophagy

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Chinese Journal of Integrative Medicine 2023年第8期29卷 699-706页

作者： xu ben YUAN Chang-wei ZHANG Jia-en Depatment of Urology Peking University First HospitalBeijing(100034)China

Objective: To explore the effect of curcumin on the proliferation of renal cell carcinoma and analyze its regulation mechanism. Methods: In RCC cell lines of A498 and 786-O, the effects of curcumin(2.5, 5, 10 μmo/L) on the proliferation were analyzed by Annexin V+PI staining. Besides, A498 was inoculated into nude mice to establish tumorigenic models, and the model mice were treated with different concentrations of curcumin(100, 200, and 400 mg/kg), once daily for 30 days. Then the tumor diameter was measured, the tumor cells were observed by hematoxylin-eosin staining, and the protein expressions of miR-148 and ADAMTS18were detected by immunohistochemistry. In vitro, after transfection of miR-148 mimics, miR-148 inhibitor or si-ADAMTS18 in cell lines, the expression of ADAMTS18 was examined by Western blotting and the cell survival rate was analyzed using MTT. Subsequently, Western blot analysis was again used to examine the autophagy phenomenon by measuring the relative expression level of LC3-Ⅱ/LC3-Ⅰ;autophagy-associated genes,including those of Beclin-1 and ATG5, were also examined when miR-148 was silenced in both cell lines with curcumin treatment. Results: Curcumin could inhibit the proliferation of RCC in cell lines and nude mice. The expressions of miR-148 and ADAMTS18 were upregulated after curcumin treatment both in vitro and in vivo(P<0.05). The cell survival rate was dramatically declined upon miR-148 or ADAMTS18 upregulated. However,si-ADAMTS18 treatment or miR-148 inhibitor reversed these results, that is, both of them promoted the cell survival rate. Conclusion: Curcumin can inhibit the proliferation of renal cell carcinoma by regulating the miR-148/ADAMTS18 axis through the suppression of autophagy in vitro and in vivo. There may exist a positive feedback loop between mi R-148 and ADAMTS18 gene in RCC.

关键词： curcumin renal cell carcinoma MiR-148 ADAMTS18 gene autophagy

Curcumin Inhibits Viability of Clear Cell Renal Cell Carcinoma by Down-Regulating ADAMTS18 Gene Methylation through NF-κB and AKT Signaling Pathway

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Chinese Journal of Integrative Medicine 2022年第5期28卷 419-424页

作者： xu ben PENG Yi-ji ZHU Wei-jie Department of Urology Peking University First Hospital and Institute of UrologyPeking UniversityNational Urological Cancer CenterBeijing(100034)China

Objective:To investigate the effect of curcumin on viability of clear cell renal cell carcinoma(cc RCC)and analyze its possible ***:In cell lines of A498 and 786-O,the effects of curcumin(1.25,2.5,5 and 10μmol/L)on the viability of cc RCC were analyzed at 24,48 and 72 h by MTT *** protein expression levels of ADAMTS18 gene,p65,phosphorylation p65(pp65),AKT,phosphorylation AKT(p AKT)and matrix metallopeptidase 2(MMP-2)before and after curcumin(10μmol/L)treatment were examined by Western ***-time PCR and methylation specific PCR(MSP)were applied to analyze the expression and methylation level of ADAMTS18 gene before and after curcumin treatment(10μmol/L).Results:Curcumin significantly inhibited the viability of A498 and 786-O cell lines in a dose-and time-dependent manner(P<0.01).Up-regulation of ADAMTS18 gene expression with down-regulation of ADAMTS18 gene methylation was reflected after curcumin treatment,accompanied by down-regulation of nuclear factorκB(NF-κk B)related protein(p65 and pp65),AKT related protein(AKT and p AKT),and NF-κB/AKT common related protein *** ADAMTS18 gene overexpressed,the expression levels of p65,AKT and MMP2 were downregulated,of which were conversely up-regulated in silenced ADAMTS18(sh-ADAMTS18).The expression of pp65,p AKT and MMP2 in sh-ADAMTS18 was down-regulated after being treated with PDTC(NF-κB inhibitor)and LY294002(AKT inhibitor).Conclusion:Curcumin could inhibit the viability of cc RCC by down-regulating ADAMTS18 gene methylation though NF-κB and AKT signaling pathway.

关键词： curcumin clear cell renal cell carcinoma ADAMTS18 gene methylation signaling pathway

Characterizations and Extensions of Lipschitz-α Operators

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Acta Mathematica Sinica,English Series 2006年第3期22卷 671-678页

作者： Huai Xin CAO Jian Hua ZHANG Zong ben xu College of Mathematics and Information Science Shaanxi Normal University Faculty of Science Xi'an Jiaotong University

In this work, we prove that a map F from a compact metric space K into a Banach space X over F is a Lipschitz-α operator if and only if for each σ in X^＊ the map σoF is a Lipschitz-α function on K. In the case that K = [a, b], we show that a map f from [a, b] into X is a Lipschitz-1 operator if and only if it is absolutely continuous and the map σ→ （σ o f）＇ is a bounded linear operator from X^＊ into L^∞（[a, b]）. When K is a compact subset of a finite interval （a, b） and 0 〈 α ≤ 1, we show that every Lipschitz-α operator f from K into X can be extended as a Lipschitz-α operator F from [a, b] into X with Lα（f） ≤ Lα（F） ≤ 3^1-α Lα（f）. A similar extension theorem for a little Lipschitz-α operator is also obtained.

关键词： Characterization Extension Lipschitz-α operator

Solubility and Anisotropic Migration Behaviors of Helium in bcc Iron Under Strain

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Acta Metallurgica Sinica(English Letters) 2018年第2期31卷 199-207页

作者： Yue Yu ben xu Hao Chen Zhi-Gang Yang Chi Zhang Key Laboratory of Advanced Materials of Ministry of Education School of Materials Science and EngineeringTsinghua University

The different solution and migration behaviors of tetrahedral and octahedral interstitial helium in bcc iron have been investigated by using first principles calculations. We showed that the tetrahedral site has less charge transfer and less redistribution of the density of states but stronger bonding and a lower solution energy. This is due to the coupling between the symmetrical facts of the two interstitial atoms and the 3 d orbitals of Fe atoms. The solution energies of both sites are not significantly influenced by applied normal strains of 2% and 4%. In contrast, the migration barriers have the reverse trends for different migration directions under strain, which can be explained by an anisotropic elastic energy change and charge transfer. The lower migration energy along certain directions under strain can facilitate the segregation of helium and the formation of helium bubbles.

关键词： Strain Point defects Migration Density functional theory (DFT) Iron Helium embrittlement

Stress field interaction during propagation of adjacent tensile twinning nuclei in magnesium

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Rare Metals 2019年第8期38卷 721-732页

作者： Zhe Li ben xu Qi Sun Qiu-Lin Li Wei Liu School of Materials Science and Engineering Tsinghua University Beijing 100084 China Daya Bay Nuclear Power Plant China Nuclear Power Engineering Co. Ltd Shenzhen 518000 China Joint Laboratory of Nuclear Materials and Service Safety Graduate School at Shenzhen Tsinghua University Shenzhen 518000 China

The shear stress field proximity to the twinning and prismatic/basal interfaces of {1012} tensile twins is shown by molecular dynamics *** stress field interacts and influences the twinning growth mode in the subsequent deformation process,which is simulated by changing the relative positions of the *** asymmetrical growth mode appears,in which the growth of one twin is predominant over the other when they are oriented at 45° to each *** growth mode is sensitive to the simulation temperature and strain rate and can be attributed to the interaction of the stress field proximity to the prismatic/basal interfaces and twinning planes.

关键词： Twinning Twin-twin interaction Stress field Molecular dynamics Magnesium

Curcumin Interferes with TGF-β1-Induced Fibrosis in NRK-49F Cells by Reversing ADAMTS18 Gene Methylation

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Chinese Journal of Integrative Medicine 2024年第7期30卷 600-607页

作者： xu ben ZHANG Jia-en YE Lin YUAN Chang-wei Department of Urology Peking University First Hospital and Institute of UrologyPeking UniversityNational Urological Cancer CenterBeijing100034China

Objective To explore the molecular mechanism by which curcumin affects renal interstitial fibrosis(RIF)progression by regulating ADAM metallopeptidase with thrombospondin type 1 motif 18(ADAMTS18)*** NRK-49F cells RIF model were induced with transforming growth factorβ1(TGF-β1).Effects of different concentrations of curcumin(0,10,20,and 30μmol/L)on cell proliferation,cell cycle,cell apoptosis as well as cyclin D1 expression were analyzed by cell counting kit-8,flow cytometry and Western blot,***18 methylation levels were determined by methylation-specific polymerase chain ***18,fibronectin(FN),type I collagen(Col-I)and alpha-smooth muscle actin(α-SMA)mRNA and protein expressions were analyzed by real-time PCR(RT-PCR)and Western blot,***,cells were treated with 50 mmol/L 5-aza-2′-deoxycytidine(5-aza-dC,demethylation agent)for 72 *** of curcumin on extracellular matrix(ECM)deposition was evaluated by immunochemical staining and Western ***-49F cells were transfected with ADAMTS18 small interfering RNA and grouped into a normal control,ADAMTS18-knock-out(KO),and ADAMTS18-KO+30μmol/L curcumin groups,and whether curcumin can reverse the effect of ADAMTS18 knockdown on RIF was *** Compared with the control group,TGF-β1 significantly inhibited the proliferation of NRK-49F cells,blocked the G1/G0 phase,promoted cell apoptosis and inhibited cyclin D1 expression(P<0.01).Among the different concentrations of curcumin,30μmol/L curcumin significantly reversed these processes(P<0.01).Immunochemical staining and Western blot results showed that curcumin significantly inhibited the deposition of FN,Col-I andα-SMA(P<0.01).Curcumin and 5-zaz-dC had synergistic effects,promoting ADAMTS18 expression,removing ADAMTS18 methylation,and reducing ECM ***18 knockdown promoted ECM accumulation,and curcumin reversed this process(P<0.01).Conclusion TGF-β1-induced fibrosis in NRK-49F ***

关键词： renal fibrosis curcumin Chinese medicine ADAMTS18 methylation modification