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Journal of Materials Science & Technology 2020年第24期59卷 173-179页

作者： H.Dong y.z.chen z.R.zhang G.B.Shan W.X.zhang F.Liu State Key Lab.of Solidification Processing Northwestern Polytechnical UniversityXi’an 710072China yangtze River Delta Research Institute of NPU Taicang 215400China

The eutectic Ag-Cu alloys exhibiting fine Ag-Cu lamellar eutectic structure formed upon rapid solidification have great potentials being used in various engineering ***,the desired fine primary lamellar eutectic structure(PLES)is usually replaced by a coarse anomalous eutectic structure(AES)when the undercooling prior to solidification exceeds a certain *** forming mechanism of AES in the undercooled eutectic Ag-Cu alloy has been a controversial *** this work,the undercooled Ag-39.9 at.% Cu eutectic alloy is solidified under different cooling conditions by using techniques of melt fluxing and copper mold *** results show that the coupled eutectic growth of this alloy undergoes a transition from a slow eutectic-cellular growth(ECG)to a rapid eutectic-dendritic growth(EDG)above a undercooling of 72 K,accompanying with an abrupt change of the distribution and amount of AES in as-solidified *** kinds of primary lamellar eutectic structures are formed by ECG and EDG during recalescence,*** destabilization of PLES that causes the formation of AES is ascribed to two different mechanisms based on the microstructural examination and theoretical *** 72 K,the destabilization of PLES formed by slow ECG is caused by the mechanism of"termination migration"driven by interfacial *** above 72 K,the destabilization of PLES formed by rapid EDG is attributed to the unstable perturbation of interface driven by interfacial energy and solute supersaturation.

关键词： Ag-Cu alloys Rapid solidification Undercooling Eutectics Destabilization

Influence of Al_2O_3 particle pinning on thermal stability of nanocrystalline Fe

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Journal of Materials Science & Technology 2018年第4期34卷 599-604页

作者： G.B.Shan y.z.chen M.M.Gong H.Dong B.Li F.Liu State Key Laboratory of Solidification Processing Northwestern Polytechnical University

Second-phase particle pinning has been well known as a mechanism impeding grain boundary （GB） migration, and thus, is documented as an efficient approach for stabilizing nanocrystalline （NC） materials at elevated temperatures. The pinning force exerted by interaction between small dispersed particles and GBs strongly depends on size and volume fraction of the particles. Since metallic oxides, e.g. Al2O3, exhibit great structural stability and high resistance against coarsening at high temperatures, they are expected as effective stabilizers for NC materials. In this work, NC composites consisting of NC Fe and Al2O3 nanoparticIes with different amounts and sizes were prepared by high energy ball milling and annealed at various temperatures （Tann） for different time periods （tann）. Microstructures of the ball milled and annealed samples were examined by X-ray diffraction and transmission electron microscopy. The results show that the addition of Al2O3 nanoparticles not only enhances the thermal stability of NC Fe grains but also reduces their coarsening rate at elevated temperatures, and reducing the particle size and/or increasing its amount enhance the stabilizing effect of the Al2O3 particles on the NC Fe grains.

关键词： Iron Nanocrystalline materials Ball milling zener pinning Grain growth Thermal stability

On the mechanism of Si-promoted destabilization of TiC_(x)particles in Al alloys

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Journal of Materials Science & Technology 2023年第34期165卷 17-26页

作者： H.Dong y.C.Guo y.z.chen F.Xia Q.Q.Guo Q.chen G.L.Li J.y.zhao y.zhong J.P.Li School of Materials and Chemical Engineering Xi’an Technological UniversityXi’an 710021China State Key Lab.of Solidification Processing Northwestern Polytechnical UniversityXi’an 710072China School of Science Xi’an University of Science and TechnologyXi’an 710054China

TiC_(x)is an excellent composite strengthening particle and grain refiner for Al ***,the stability of TiC_(x)is poor when solute Si exists in Al alloy melts,which significantly depresses its strengthening and grain refining *** this work,the destabilization mechanisms of the TiC_(x)particles in Al-Si alloy melt with a composition of Al-7Si-7.5TiC were explored via experiments,first-principles calculations and thermodynamic *** experimental results show that Si atoms diffuse into TiC_(x)and Ti atoms are released into the Al melt to form a Ti-rich transition zone during the insulation of TiC_(x)in Al-Si melt,and the TiAlySiz and Al_(4)C_(3)phases are solidified in the Ti-rich zone and at Ti-rich zone/TiC_(x)interface,*** first principles calculations show that the low formation energy of C vacancies facilitates the rapid diffusion of Si atoms in TiC_(x),while the doping of Si atoms reduces the energy barrier of diffusion of Ti atoms in TiC_(x)and promotes the formation of Ti-rich *** thermodynamic calculations show that the wide crystallization temperature range of the destabilized product TiAlySiz phase is the key to continuous decomposition of TiC_(x)*** addition,the driving force of the main destabilization reaction of TiC_(x)in the Al-Si alloys is about 44 times higher than that in the Al alloys without Si *** indicates that the presence of solute Si remarkably promotes the subsequent decomposition process of TiC_(x)in the Al-Si alloy melts.

关键词： Al-Si alloy TiC_(x)particles Destabilization First principles calculations Thermodynamics

Effects of dealloying and heat treatment parameters on microstructures of nanoporous Pd

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Journal of Materials Science & Technology 2020年第13期47卷 123-129页

作者： y.z.chen X.y.Ma W.X.zhang H.Dong G.B.Shan y.B.Cong C.Li C.L.yang F.Liu State Key Lab.of Solidification Processing Northwestern Polytechnical University710072 Xi’anChina

Microstructures of nanoporous Pd are essentially important for its physical and chemical *** this work,we show that the microstructures of nanoporous Pd can be tuned by adjusting compositions of the precursor alloys,and dealloying and heat treatment *** the ligament and pore sizes decrease with increasing the electrochemical potential upon dealloying and the concentration of noble component in the precursor *** treatment causes coarsening of the nanoporous *** a critical temperature,the nanoporous structures are subjected to significant *** the critical temperature,surface diffusion is believed to dominate the coarsening *** the critical temperature,the nanoporous structure coarsens remarkably at a rather high rate,which is ascribed to a multiple-mechanism controlled process.

关键词： Nanoporous metals Microstructure Dealloying Kinetics Coarsening

PPAR Signaling Pathway may be an Important Predictor of Breast Cancer Response to Neoadjuvant Chemotherapy

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PPAR Signaling Pathway may be an Important Predictor of Brea...

Rational design of AgGaS/znS/znS quantum dots with a near-unity photoluminescence quantum yield via double shelling scheme

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作者： y.z.chen J.y.Xue C.M.chen B.L.yang G.y.Liu z.z.Shen z.M.Shao J.Wu Q.H.Xu F.Wu F.Liu X.ye X.Meng Department of Breast Surgery Fudan University Shanghai Cancer Center Department of Oncology Shanghai Medical CollegeFudan University Department of Oncology Surgery First Affiliated Hospital of Wenzhou Medical College2 Fu Xue Lane Fudan University Shanghai Cancer Center-Institut Mérieux Laboratory Fudan University Shanghai Cancer Center

Purpose Neoadjuvant chemotherapy for advanced breast cancer may improve the radicality for a subset of patients,but others may suffer from severe adverse drug reactions without any *** predict the responses to chemotherapy,we performed a phaseⅡtrial of neoadjuvant chemotherapy using a weekly PCb regimen[paclitaxel (Taxol) plus carboplatin]for stageⅡ/Ⅲbreast cancer and assessed the correlation between baseline gene expression and the tumor response to treatment. Methods A total of 61 patients with stage II-Ⅲbreast cancer were included and administered four cycles of preoperative *** performed a gene expression analysis using Affymetrix HG-U133 Plus 2.0 GeneChip arrays in 31 breast cancer *** expressed genes(DEGs) were identified by the Significance Analysis of Microarrays(SAM) program using a false discovery rate(FDR) of *** Functional Annotation Tool in the DAVID Bioinformatics Resources was used to perform the gene functional enrichment *** other 30 patients(15 pCR and 15 non-pCR patients) were available as an independent validation set to test the selected DEGs by quantitative real-time PCR analysis(qRT-PCR). Results By analyzing six pathological complete response(pCR) patients and 25 patients with non-pCR,300 probes(231 genes) were identified as differentially expressed between pCR and residual disease by the SAM program when the fold change was>*** gene functional enrichment analysis revealed 15 prominent gene categories that were different between pCR and non-pCR patients,most notably the genes involved in the PPAR(Peroxisome Proliferator Activated Receptor),DNA repair and ER signal pathways and in the immune-related gene *** qRT-PCR analysis results for the genes in the PPAR pathway(LPL,SORBSl,PLTP,SCD5,MMPl and CSTA) in independent validation set were consistent with the results from the microarray data analysis. Conclusion In the present study,we identified a number of gene categories pertinent to the ther

关键词： Neoadjuvant Gene expression Chemotherapy response PPAR pathway DNA repair

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Journal of Materials Science & Technology 2024年第2期169卷 235-242页

作者： H.X.Lu H.Liu z.z.Fu y.y.chen H.Q.Dai z.Hu W.L.zhang R.Q.Guo Institute for Electric Light Sources School of Information Science and TechnologyFudan UniversityShanghai 200433China Institute of Future Lighting Academy for Engineering and TechnologyFudan UniversityShanghai 200433China yiwu Research Institute of Fudan University YiwuZhejiang 322000China zhongshan-Fudan Joint Innovation Center Zhongshan 528437China

In this study,a two-step method was used to synthesize highly luminescent AgGaS/znS/znS quantum dots(QDs).In the first step,an inner znS shell was formed via a one-pot method,which resulted in a smaller lattice mismatch between the AgGaS core and the outer znS shell,thereby facilitating the formation of a thick outer *** the two-step shelling process,the synthesized AgGaS/znS/znS QDs showed an excellent photoluminescence quantum yield(PLQy)of 96.4%with a peak wavelength of 508 nm,repre-senting the highest PLQy reported thus far for AgGaS ***,the effect of halogen ions in zn precursors on the shelling process was *** was proposed that the capacity of halogen ions to coordinate with the QDs influenced the balance between zn cation diffusion and znS shelling ***,the znS shelling reaction was dominant when znCl_(2)was employed,while zn cation diffusion was the dominant process under the I^(−)-rich *** work provides insights into the interfacial restructuring during the znS shelling and offers a clear map for the tailored synthesis of core/shell QDs.

关键词： AgGaS Quantum dots Photoluminescence Core/shell Alloyed core/shell interface

Rescattering of stimulated Raman side scattering in nonuniform plasmas

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Matter and Radiation at Extremes 2024年第5期9卷 68-76页

作者： S.Tan Q.Wang y.chen W.B.yao C.z.Xiao J.F.Myatt School of Physics and Electronics Hunan UniversityChangsha 410082China Institute of Applied Physics and Computational Mathematics Beijing 100094China School of Electrical and Information Engineering Anhui University of Science and TechnologyHuainanAnhui 232001China Department of Electrical and Computer Engineering University of Alberta9211116 St.NWEdmontonAlberta T6G 1H9Canada

Rescattering of stimulated Raman side scattering(SRSS)is observed for the first time via two-dimensional(2D)particle-in-cell(PIC)*** construct a theoretical model for the rescattering process,which can predict the region of occurrence of mth-order SRSS and estimate its *** rescattering process is identified by the 2D PIC simulations under typical conditions of a direct-drive inertial confinement fusion *** electrons produced by second-order SRSS propagate nearly perpendicular to the density gradient and gain nearly the same energy as in first-order SRSS,but there is no cascade acceleration to produce superhot *** studies for a wide range of ignition conditions show that SRSS and associated rescatterings are robust and important processes in inertial confinement fusion.

关键词： nonuniform acceleration scattering

Granger causal representation learning for groups of time series

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Science China(Information Sciences) 2024年第5期67卷 56-68页

作者： Ruichu CAI yunjin WU Xiaokai HUANG Wei chen Tom z.J.FU zhifeng HAO School of Computer Science Guangdong University of Technology Peng cheng Laboratory College of Science Shantou University

Discovering causality from multivariate time series is an important but challenging *** existing methods focus on estimating the Granger causal structures among multivariate time series,while ignoring the prior knowledge of these time series, e.g., the group of the time series. Focusing on discovering the Granger causal structures among groups of time series, we propose a Granger causal representation learning method to solve this problem. First, we use the multiset canonical correlation analysis method to learn the Granger causal representation of each group of time series. Then, we model the Granger causal relationships among the learned Granger causal representations using a recurrent neural network with temporal information. Finally, we formulate the above two stages into one unified optimization problem, which is efficiently solved using the augmented Lagrangian method. We conduct extensive experiments on synthetic and real-world datasets to validate the correctness and effectiveness of the proposed method.

关键词： Granger causal discovery Granger causal representation learning time series data recurrent neural network multiset canonical correlation analysis

Structural basis for polyuridine tract recognition by SARS-CoV-2 Nsp15

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Protein & Cell 2024年第7期15卷 547-552页

作者： Fumiaki Ito Hanjing yang z.Hong zhou Xiaojiang S.chen Molecular and Computational Biology Department of Biological SciencesUniversity of Southern CaliforniaLos AngelesCA 90089United States Department of Microbiology Immunology and Molecular GeneticsUniversity of CaliforniaLos AngelesCA 90095United States California NanoSystems Institute University of CaliforniaLos AngelesCA90095United States Genetic Molecular and Cellular Biology ProgramKeck School of MedicineUniversity of Southern CaliforniaLos AngelesCA 90089United States Norris Comprehensive Cancer Center University of Southern CaliforniaLos AngelesCA 90089United States Center of Excellence in NanoBiophysics University of Southern CaliforniaLos AngelesCA 90089United States

Dear Editor,Coronaviruses have evolved a wide array of tactics to evade host antiviral *** host cells detect invading foreign nucleic acids including viral genome and viral replication intermediates,they activate interferon(IFN)signaling via cytoplasmic pattern recognition receptors(Kang et al.,2002;Kato et al.,2006).Remarkable stealth activities exhibited by coronaviruses are facilitated by a series of non-structural proteins(Nsps),such as Nsp15(Deng and Baker,2018;Deng et al.,2019;Hackbart et al.,2020),which is a uridine-specific endoribonuclease that mediates evasion of host detection of viral double-stranded RNA(dsRNA)(Bhardwaj et al.,2004;Deng et al.,2017;Frazier et al.,2021;Ivanov et al.,2004).Nsp15 targets a polyuridine[poly(U)]tract on the coronavirus negative strand RNA(Hackbart et al.,2020).Nsp15 limits the abundance and length of poly(U)within the negative strand RNA 5ʹ-extension by trimming down the initially synthesized poly(U)lead sequence to the optimal length that can suppress dsRNA formation but still serves as a template for poly(A)tail of the positive strand genome of the coronaviruses(Hofmann and Brian,1991).

关键词： p15 interferon template

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Role of bisphosphonates in osteoporosis caused by adult growth hormone deficiency

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zhong nan da xue xue bao. yi xue ban = Journal of Central South University. Medical sciences 2024年第6期49卷 839-847页

作者： cheng z. Li J. chen z. Ren W. Department of Endocrinology Chongqing Traditional Chinese Medicine Hospital 400011 Chongqing China Department of Endocrinology First Affiliated Hospital of Chongqing Medical University 400016 Chongqing China

近年来，生长激素和胰岛素样生长因子已成为骨代谢和重塑的关键调节剂，对于生命各阶段健康骨量的维持均至关重要。研究表明，成人生长激素缺乏会引发骨重塑变化，显著改变骨微结构并增加骨折风险。虽然重组人生长激素替代疗法可以减轻... 详细信息

近年来，生长激素和胰岛素样生长因子已成为骨代谢和重塑的关键调节剂，对于生命各阶段健康骨量的维持均至关重要。研究表明，成人生长激素缺乏会引发骨重塑变化，显著改变骨微结构并增加骨折风险。虽然重组人生长激素替代疗法可以减轻这些负面影响，提高骨密度并降低骨折风险，但其治疗骨质疏松症的效果，特别是对于已有生长激素缺乏症的成年人，似乎有限。双膦酸盐通过抑制破骨细胞中的法尼醇焦磷酸合酶起抗骨吸收的作用，临床试验已证实其可有效改善骨质疏松。因此，对患有骨质疏松的成人生长激素缺乏症患者，建议在使用生长激素替代疗法的同时使用双膦酸盐。.; In recent years, growth hormone and insulin-like growth factors have become key regulators of bone metabolism and remodeling, crucial for maintaining healthy bone mass throughout life. Studies have shown that adult growth hormone deficiency leads to alterations in bone remodeling, significantly affecting bone microarchitecture and increasing fracture risk. Although recombinant human growth hormone replacement therapy can mitigate these adverse effects, improving bone density, and reduce fracture risk, its effectiveness in treating osteoporosis, especially in adults with established growth hormone deficiency, seems limited. Bisphosphonates inhibit bone resorption by targeting farnesyl pyrophosphate synthase in osteoclasts, and clinical trials have confirmed their efficacy in improving osteoporosis. Therefore, for adult growth hormone deficiency patients with osteoporosis, the use of bisphosphonates alongside growth hormone replacement therapy is recommended.

关键词： adult growth hormone deficiency bisphosphonates growth hormone insulin-like growth factor 1 osteoporosis skeleton