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An atomistic approach for the structural and electronic properties of twisted bilayer graphene-boron nitride heterostructures

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npj Computational Materials 2022年第1期8卷 687-696页

作者： Min Long Pierre A.Pantaleón Zhen zhan Francisco Guinea JoseÁngel Silva-Guillén Shengjun Yuan Key Laboratory of Artificial Micro-and Nano-structures of Ministry of Education and School of Physics and Technology Wuhan UniversityWuhan430072China Imdea Nanoscience C/Faraday 928015MadridSpain Donostia International Physics Center Paseo Manuel de Lardizábal 420018San SebastiánSpain Ikerbasque Basque Foundation for Science48009BilbaoSpain Wuhan Institute of Quantum Technology Wuhan430206China

Twisted bilayer graphene(TBG)has taken the spotlight in the condensed matter community since the discovery of correlated *** this work,we study heterostructures of TBG and hexagonal boron nitride(hBN)using an atomistic tight-binding model together with semi-classical molecular dynamics to consider relaxation *** hBN substrate has significant effects on the band structure of TBG even in the case where TBG and hBN are not ***,the substrate induces a large mass gap and strong pseudo-magnetic fields that break the layer ***,such degeneracy can be recovered with a second hBN ***,we develop a continuum model that describes the tight-binding band *** results show that a real-space tight-binding model in combination with semi-classical molecular dynamics is a powerful tool to study the electronic properties of moiréheterostructures,and to explain experimental results in which the effect of the substrate plays an important role.

关键词： boron electronic twisted

Targeted methylation sequencing reveals dysregulated Wnt signaling in Parkinson disease

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Journal of Genetics and Genomics 2016年第10期43卷 587-592页

作者： Lusi zhang Jie Deng Qian Pan Yan zhan Jian-Bing Fan Kun zhang Zhuohua zhang Institute of Precision Medicine The Xiangya Hospital State Key Laboratory of Medical Genetics Xiangya Medical School Central South University Department of Bioengineering University of California at San Diego Anchor Dx Corporation International Bio-island

Parkinson disease（PD） is a progressive neurodegenerative movement disorder. Both environmental and genetic factors play important roles in PD etiology. A number of environmental toxins cause parkinsonism in human and animal models. Genetic studies of rare early onset familial PD cases resulted in identification of disease-linked mutations in multiple genes. Nevertheless, the potential interaction between environment and genetics in PD pathogenesis remains largely unknown. We hypothesized that environmental factors induce abnormal epigenetic regulation that is involved in the pathogenesis of both familial and sporadic PD. We determined the global methylation status of 80,000e110,000 Cp G sites in each of the five sporadic PD patient brains and five age and postmodern interval matched control brains utilizing bisulfite padlock sequencing. Multiple genes involved in neurogenesis, particularly the ones in the Wnt signaling pathway, were hypermethylated in PD brains compared to their matched control brains. Consistent with the DNA methylation changes, marked reduction of protein expression was observed for four Wnt and neurogenesis related genes（FOXC1, NEURG2, SPRY1, and CTNNB1） in midbrain dopaminergic（DA） neurons of PD. The treatment of low concentration of 1-methyl-4-phenylpyridinium（MPPt） for cells resulted in downregulation of Wnt related genes. The study revealed an important link between the epigenetic disregulation of Wnt signaling and the pathogenesis and progression of PD.

关键词： Epigenetic regulation Neurodegenerative diseases Environmental toxins Neurogenesis

Accuracy of physical examination, ultrasonography, and magnetic resonance imaging in predicting response to neo-adjuvant chemotherapy for breast cancer

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Chinese Medical Journal 2012年第11期125卷 1862-1866页

作者： CHEN Man zhan Wei-wei HAN Bao-san FEI Xiao-chun JIN Xiao-long CHAI Wei-min WANG Deng-bing SHEN Kun-wei WANG Wen-ping Department of Diagnostic Ultrasound Zhong Shan Hospital School of Medicine Fudan University Shanghai 200032 China Department of Diagnostic Ultrasound Rui Jin Hospital School of Medicine Shanghai Jiao Tong University Shanghai 200025 China Department of Comprehensive Breast Health Center Rui Jin Hospital School of Medicine Shanghai Jiao Tong University Shanghai 200025 China Department of Pathology Rui Jin Hospital School of Medicine Shanghai Jiao Tong University Shanghai 200025 China Department of Radiology Rui Jin Hospital School of Medicine Shanghai Jiao Tong University Shanghai 200025 China

Background Accurate evaluation of response following chemotherapy treatment is essential for surgical decision making in patients with breast cancer. Modalities that have been used to monitor response to neo-adjuvant chemotherapy （NAC） include physical examination （PE）, ultrasound （US）, and magnetic resonance imaging （MRI）. The purpose of this study was to evaluate the accuracy of PE, US, and MRI in predicting the response to NAC in patients with breast cancer. Methods According to the response evaluation criteria in solid tumors guidelines, the largest unidimensional measurement of the tumor diameter evaluated by PE, US, and MRI before and after NAC was classified into four grades, including clinical complete response, clinical partial response, clinical progressive disease, clinical stable disease, and compared with the final histopathological examination. Results Of the 64 patients who received NAC, the pathologic complete response （pCR） was shown in 13 of 64 patients （20%）. The sensitivity of PE, US, and MRI in predicting the major pathologic response was 73%, 75%, and 80%, respectively, and the specificity was 45%, 50%, and 50% respectively. For predicting a pCR, the sensitivity of PE, US, and MRI was 46%, 46%, and 39%, respectively, and the specificity was 65%, 98%, and 92% respectively. Conclusions Compared with final pathologic findings, all these three clinical and imaging modalities tended to obviously underestimate the pCR rate. A more appropriate, universal, and practical standard by clinical and imaging modalities in predicting the response to neo-adjuvant chemotherapy in vivo is essential.

关键词： breast cancer neo-adjuvant chemotherapy physical examination, ultrasonography magnetic resonance imaging

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基于连续损伤的岩石渗流有限元分析

工程力学 2016年第11期33卷 29-37页

作者：王永亮柳占立林三春庄茁清华大学航天航空学院应用力学教育部重点实验室北京100084

该文基于连续损伤力学,建立了含损伤的岩石渗流模型,研究岩石损伤破坏并分析其渗流特性。该文采用Weibull分布函数来模拟岩石弹性模量和强度的非均质特性,利用Biot本构关系建立含孔隙结构的弹性变形方程,结合Drucker-Prager强度准则、... 详细信息

该文基于连续损伤力学,建立了含损伤的岩石渗流模型,研究岩石损伤破坏并分析其渗流特性。该文采用Weibull分布函数来模拟岩石弹性模量和强度的非均质特性,利用Biot本构关系建立含孔隙结构的弹性变形方程,结合Drucker-Prager强度准则、统计强度理论和连续损伤理论推导出岩石连续损伤演化控制方程及其定解条件,进而采用有限元法对其求解。该文给出的数值算例结果表明所提出的含损伤渗流模型适用于研究岩石的渗流特性,分析结果与实验数据吻合较好,且该求解方法可以对岩石体积压裂、岩层弱面进行可靠、有效的数值分析。

关键词：连续损伤 Weibull分布岩石渗流有限元

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基于CPLD的LED芯片光谱采集系统的研究

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光谱学与光谱分析 2010年第3期30卷 842-845页

作者：石炜周大兵董占民孙红三郗安民内蒙古科技大学机械工程学院内蒙古包头0140102 清华大学物理系北京100084 广州汽车集团乘用车有限公司广州广东510507 清华大学建筑学院北京100084 北京科技大学机械工程学院北京100083

发光二极管(light emitting diode,LED)芯片的光谱检测是LED芯片规模化制造中的一项关键技术。根据光谱测量原理,针对LED芯片光谱测量应用的要求,文章研究了基于复杂可编程逻辑器件(com-plex programmable logic device,CPLD)的LED芯片... 详细信息

发光二极管(light emitting diode,LED)芯片的光谱检测是LED芯片规模化制造中的一项关键技术。根据光谱测量原理,针对LED芯片光谱测量应用的要求,文章研究了基于复杂可编程逻辑器件(com-plex programmable logic device,CPLD)的LED芯片光谱采集系统。以CPLD为主芯片,为线阵电荷耦合器件(charge coupled device,CCD)提供工作时序信号,同时控制信号调理、转换、传输模块中的采样率和数据的存储与传输。采用光栅单色仪作为分光器件,线阵CCD作为光电转换器件,检测LED芯片的相对光谱能量分布曲线,同时计算LED芯片光学特性的光谱参数。基于CPLD的LED芯片光谱采集系统简单、快速,同时能达到LED芯片光谱检测精度的要求。

关键词：光谱 CPLD CCD 精度

Src heterodimerically activates Lyn or Fyn to serve as targets for the diagnosis and treatment of esophageal squamous cell carcinoma

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Science China(Life Sciences) 2023年第6期66卷 1245-1263页

作者： Jing zhang Di Zhao Lingyuan zhang Yuanfan Xiao Qingnan Wu Yan Wang Jie Chen Qimin zhan Key Laboratory of Carcinogenesis and Translational Research(Ministry of Education/Beijing) Laboratory of Molecular OncologyPeking University Cancer Hospital&InstituteBeijing100142China Peking University International Cancer Institute Peking UniversityBeijing100191China Research Unit of Molecular Cancer Research Chinese Academy of Medical SciencesBeijing100142China Institute of Cancer Research Shenzhen Bay LaboratoryShenzhen518107China

Although Src is one of the oldest and most investigated oncoproteins,its function in tumor malignancy remains to be defined *** this study,we demonstrated that the inhibition of Src activity by ponatinib effectively suppressed several malignant phenotypes of esophageal squamous cell carcinoma(ESCC)both in vitro and in vivo,whereas it did not produce growthinhibitory effects on normal esophageal epithelial cells(NEECs).Importantly,we combined phosphoproteomics and several cellular and molecular biologic strategies to identify that Src interacted with the members of Src-family kinases(SFKs),such as Fyn or Lyn,to form *** interactions with Fyn and Lyn phosphorylated the tyrosine sites in SH2(Fyn Tyr^(185)or Lyn Tyr^(183))and kinase domains(Fyn Tyr^(420) or Lyn Tyr^(397)),which critically contributed to ESCC *** contrast,Src could not form heterodimers with Fyn or Lyn in *** used RNA sequencing to comprehensively demonstrate that the inhibition of Src activity effectively blocked several critical tumor-promoting pathways,such as JAK/STAT,mTOR,stemness-related,and metabolism-related *** of the real-time polymerase chain reaction(RT-PCR)assay confirmed that Lyn and Fyn were critical effectors for the Src-mediated expression of tumor growth or metastasis-related ***,results of the clinical ESCC samples showed that the hyperactivation of pSrc Tyr^(419),Fyn Tyr^(185) or Tyr^(420),and Lyn Tyr^(183)or Tyr^(397)could be biomarkers of ESCC *** study illustrates that Src/Fyn and Src/Lyn heterodimers serve as targets for the treatment of ESCC.

关键词： esophageal squamous cell carcinoma heterodimer Src-family kinase Src tyrosine phosphorylation

Tumor-associated macrophage(TAM)-derived CCL22 induces FAK addiction in esophageal squamous cell carcinoma(ESCC)

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Cellular & Molecular Immunology 2022年第9期19卷 1054-1066页

作者： Jie Chen Di Zhao Lingyuan zhang Jing zhang Yuanfan Xiao Qingnan Wu Yan Wang Qimin zhan Key Laboratory of Carcinogenesis and Translational Research(Ministry of Education/Beijing) Laboratory of Molecular OncologyPeking University Cancer Hospital&InstituteBeijing100142China Peking University International Cancer Institute Peking UniversityBeijing100191China Research Unit of Molecular Cancer Research Chinese Academy of Medical SciencesBeijingChina Institute of Cancer Research Shenzhen Bay LaboratoryShenzhen518107China

Tumor cell dependence on activated oncogenes is considered a therapeutic target,but protumorigenic microenvironment-mediated cellular addiction to specific oncogenic signaling molecules remains to be further ***,we showed that tumor-associated macrophages(TAMs)produced an abundance of C-C motif chemokine 22(CCL22),whose expression in the tumor stroma was positively associated with the level of intratumoral phospho-focal adhesion kinase(pFAK Tyr^(397)),tumor metastasis and reduced patient ***,CCL22-stimulated hyperactivation of FAK was correlated with increased malignant progression of cancer ***22-induced addiction to FAK was demonstrated by the persistent suppression of tumor progression upon FAK-specific ***,we identified that diacylglycerol kinaseα(DGKα)acted as a signaling adaptor to link the CCL22 receptor C-C motif chemokine receptor 4(CCR4)and FAK and promoted CCL22-induced activation of the FAK/AKT ***22/CCR4 signaling activated the intracellular Ca^(2+)/phospholipase C-γ1(PLC-γ1)axis to stimulate the phosphorylation of DGKαat a tyrosine residue(Tyr^(335))and promoted the translocation of DGKαto the plasma membrane to assemble the DGKα/FAK signalosome,which critically contributed to regulating sensitivity to FAK inhibitors in cancer *** identification of TAM-driven intratumoral FAK addiction provides opportunities for utilizing the tumor-promoting microenvironment to achieve striking anticancer effects.

关键词： Tumor-associated macrophages Esophageal squamous cell carcinoma FAK Oncogene addiction

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三角范数的构造

西北大学学报（自然科学版） 2009年第2期39卷 177-180页

作者：薛占军刘三阳西安电子科技大学数学科学系陕西西安710071

目的研究三角范数的构造问题。方法借助半群代数理论的结果与方法进行构造。结果给出几种构造三角范数的方法,构造出三角范数族Tc且满足对任意的c,d∈(0,1),c≤d当且仅当Td≤Tc。结论由已知的三角范数可以构造新三角范数。

关键词：三角范数三角子范数半群

A Spatially Weighted Degree Model for Network Vulnerability Analysis

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Geo-Spatial Information Science 2011年第4期14卷 274-281页

作者： WAN Neng1,zhan F.Benjamin1,2,CAI Zhongliang2 1.School Texas Center for Geographic Information Science,Department of Geography,Texas State University,san Marcos,TX 78666,USA 2.School of Resource and Environmental Science,Wuhan University,129 Luoyu Road,Wuhan 430079,China School Texas Center for Geographic Information Science Department of Geography Texas State University San Marcos USA School of Resource and Environmental Science Wuhan University Wuhan China

Using degree distribution to assess network vulnerability represents a promising direction of network ***,the traditional degree distribution model is inadequate for analyzing the vulnerability of spatial networks because it does not take into consideration the geographical aspects of spatial *** paper proposes a spatially weighted degree model in which both the functional class and the length of network links are considered to be important factors for determining the node degrees of spatial networks.A weight coefficient is used in this new model to account for the contribution of each factor to the node *** proposed model is compared with the traditional degree model and an accessibility-based vulnerability model in the vulnerabil-ity analysis of a highway *** results indicate that,although node degrees of spatial networks derived from the tra-ditional degree model follow a random distribution,node degrees determined by the spatially weighted model exhibit a scale-free distribution,which is a common characteristic of robust *** to the accessibility-based model,the proposed model has similar performance in identifying critical nodes but with higher computational efficiency and better ability to reveal the overall vulnerability of a spatial network.

关键词： GIS network analysis spatial analysis vulnerability analysis