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Deciphering fungal metabolon coupling tandem inverse-electrondemand Diels-Alder reaction and semipinacol rearrangement for the biosynthesis of spiro polycyclic alkaloids

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Science China Chemistry 2025年第1期68卷 288-296页

作者： Shuai Liu Wen-Qiang Xu Ying-Tong Di man-Cheng tang Ding-Kang Chen Ming-Ming Cao Yao-Wen Chang Hong-Yu tang Chun-Mao Yuan Jun-Bo Yang Zhi-Li Zuo Han Guo Zi-Fei Xu Ying Zeng Yun-Dong Wu Xiao-Jiang Hao Key Laboratory of Phytochemistry and Natural Medicines (Chinese Academy of Sciences) Kunming Institute of Botany Chinese Academy of Sciences University of Chinese Academy of Sciences Lab of Computational Chemistry and Drug Design State Key Laboratory of Chemical Oncogenomics Peking University Shenzhen Graduate School Shenzhen Bay Laboratory State Key Laboratory of Microbial Metabolism School of Life Sciences & Biotechnology Shanghai Jiao Tong University State Key Laboratory of Functions and Applications of Medicinal Plants Guizhou Medical University Molecular Biology Experimental Center Germplasm Bank of Wild Species in Southwest China Kunming Institute of Botany Chinese Academy of Sciences Yunnan Key Laboratory for Wild Plant Resources Kunming Institute of Botany Chinese Academy of Sciences Research Unit of Chemical Biology of Natural Anti-Virus Products Chinese Academy of Medical Sciences

In the intricate process of natural product biosynthesis, a metabolon can enhance metabolic flux by associating sequential enzymes. A fungal metabolon, comprising of flavin-dependent monooxygenase Spe F and P450 monooxygenase Spe G, is identified in the biosynthesis of spiro polycyclic alkaloids(+)-notoamide B and its diastereomer(+)-versicolamide B. Using notoamide E as a substance, Spe F/Spe G metabolon can control the stereoselectivity of its 2,3-epoxidation, followed by hydrogen atom ion at C-17 to generate reactive epoxide tau-m A with dienyl iminium unit. Subsequently,(+)-notoamide B and(+)-versicolamide B are produced via tandem nonenzymatic inverse-electron-demand Diels-Alder reaction and semipinacol rearrangement. This provides the first example of metabolon in the biosynthesis of spiro-prenylated indole alkaloids.

关键词： metabolon Diels-Alder reaction semipinacol rearrangement biosynthesis notoamides spiro polycyclic alkaloids

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Forms and Aesthetics of Bridges

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Engineering 2018年第2期4卷 103-112页

作者： man-Chung tang Chinese Academy of Engineering Beijing 100088 China US National Academy of Engineering Washington DC 20001 USA T.Y. Lin International Group San Francisco CA 94104 USA

The objective of a bridge design is to produce a safe bridge that is elegant and satisfies all functionality requirements, at a cost that is acceptable to the owner. A successful bridge design must be natural, simple, original, and harmonious with its surroundings. Aesthetics is not an additional consideration in the design of a bridge, but is rather an integral part of bridge design. Both the structural configuration and the aesthetics of a bridge must be considered together during the conceptual design stage. To achieve such a task, the bridge design engineer must have a good understanding of structural theory and bridge aesthetics.

关键词： Form Aesthetics Bridge Concept Design Environment

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Generalized T3-plot for testing high-dimensional normality

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Frontiers of Mathematics in China 2016年第6期11卷 1363-1363,1364-1378页

作者： Mingyao AI Jiajuan LIANG man-Lai tang LMAM School of Mathematical Sciences and Center for Statistical Science Peking University Beijing 100871 China Department of Marketing College of Business University of New Haven West Haven CT 06516 USA Department of Mathematics and Statistics School of Business Hang Seng Management College Hong Kong China

A new dimension-reduction graphical method for testing high- dimensional normality is developed by using the theory of spherical distributions and the idea of principal component analysis. The dimension reduction is realized by projecting high-dimensional data onto some selected eigenvector directions. The asymptotic statistical independence of the plotting functions on the selected eigenvector directions provides the principle for the new plot. A departure from multivariate normality of the raw data could be captured by at least one plot on the selected eigenvector direction. Acceptance regions associated with the plots are provided to enhance interpretability of the plots. Monte Carlo studies and an illustrative example show that the proposed graphical method has competitive power performance and improves the existing graphical method significantly in testing high-dimensional normality.

关键词： Dimension reduction graphical method high-dimensional data multivariate normality spherical distribution

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Design concept of the Twin River Bridges in Chongqing,China

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Frontiers of Structural and Civil Engineering 2011年第4期5卷 427-431页

作者： man-Chung tang T.Y.Lin International Corporate Headquarters Two Harrison StreetSuite 500San FranciscoCA 94105USA

The Dongshuimen Bridge over the Yangtze River and the Qiansimen Bridge over the Jialing River in Chongqing,China are located at the tip of the Yuzhong ***,they are called the Twin River *** are double deck structures carrying four lanes of traffic on their upper decks and two transit tracks on their lower *** girders are steel truss structures with orthotropic plates and the towers are made of *** were carefully considered for the design of these bridges because of their visibility in the city and their neighboring landmarks.

关键词： long span bridges partially cable-supported girder bridge cable-stayed bridge extradosed steel truss bridge aesthetics Chongqing China

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Semiparametric Quantile Modelling of Hierarchical Data

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Acta Mathematica Sinica,English Series 2009年第4期25卷 597-616页

作者： Mao Zai TIAN man Lai tang Ping Shing CHAN School of Statistics Renmin University of China Beijing 100872 P. R. China Center for Applied Statistics Renmin University of China Beijing 100872 P. R. China Department of Mathematics Hong Kong Baptist University Kowloon Hong Kong Department of Statistics The Chinese University of Hong Kong Shatin N.T. Hong Kong

The classic hierarchical linear model formulation provides a considerable flexibility for modelling the random effects structure and a powerful tool for analyzing nested data that arise in various areas such as biology, economics and education. However, it assumes the within-group errors to be independently and identically distributed （i.i.d.） and models at all levels to be linear. Most importantly, traditional hierarchical models （just like other ordinary mean regression methods） cannot characterize the entire conditional distribution of a dependent variable given a set of covariates and fail to yield robust estimators. In this article, we relax the aforementioned and normality assumptions, and develop a so-called Hierarchical Semiparametric Quantile Regression Models in which the within-group errors could be heteroscedastic and models at some levels are allowed to be nonparametric. We present the ideas with a 2-level model. The level-1 model is specified as a nonparametric model whereas level-2 model is set as a parametric model. Under the proposed semiparametric setting the vector of partial derivatives of the nonparametric function in level-1 becomes the response variable vector in level 2. The proposed method allows us to model the fixed effects in the innermost level （i.e., level 2） as a function of the covariates instead of a constant effect. We outline some mild regularity conditions required for convergence and asymptotic normality for our estimators. We illustrate our methodology with a real hierarchical data set from a laboratory study and some simulation studies.

关键词： hierarchical models quantile regression robustness

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Kernel Quantile Estimator with ICI Adaptive Bandwidth Selection Technique

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Acta Mathematica Sinica,English Series 2014年第4期30卷 710-722页

作者： Jie Yu FAN man Lai tang Mao Zai TIAN Department of Statistics University of Pittsburgh Department of Mathematics and Statistics Hang Seng Management College School of Statistics Lanzhou University of Finance and Economics Center for Applied Statistics School of StatisticsRenmin University of China

In this article, we consider a class of kernel quantile estimators which is the linear combi- nation of order statistics. This class of kernel quantile estimators can be regarded as an extension of some existing estimators. The exact mean square error expression for this class of estimators will be provided when data are uniformly distributed. The implementation of these estimators depends mostly on the bandwidth selection. We then develop an adaptive method for bandwidth selection based on the intersection confidence intervals （ICI） principle. Monte Carlo studies demonstrate that our proposed approach is comparatively remarkable. We illustrate our method with a real data set.

关键词： Adaptive bandwidth selection ICI principle kernel estimator quantiles

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Two-step Estimation for Longitudinal Data When the Working Correlation Matrix is a Linear Combination of Some Known Matrices

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Acta Mathematicae Applicatae Sinica 2019年第2期35卷 264-273页

作者： Yu-ling LI Wei GAO man-Lai tang Shu-rong ZHENG Key Laboratory for Applied Statistics of MOE School of Mathematics and StatisticsNortheast Normal University School of Applied Mathematics Beijing Normal University Department of Mathematics and Statistics Hang Seng Management College

The generalized estimating equations(GEE) approach is perhaps one of the most widely used methods for longitudinal data analysis. While the GEE method guarantees the consistency of its estimators under working correlation structure misspecification, the corresponding efficiency can be severely affected. In this paper, we propose a new two-step estimation method in which the correlation matrix is assumed to be a linear combination of some known working matrices. Asymptotic properties of the new estimators are *** studies are conducted to examine the performance of the proposed estimators. We illustrate the methodology with an epileptic data set.

关键词： generalized estimating equations longitudinal data quadratic inference functions quasi-likelihood two-step estimation

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‘One Health' for the people of Hong Kong and the world

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Science China(Life Sciences) 2016年第10期59卷 1068-1070页

作者： Kin-Hang Kok Hei-man Vincent tang Dong-Yan Jin Department of Biochemistry University of Hong Kong

Translational medicine refers to the conversion of scientific discoveries into improvements in medical practice. ＇From bench to bedside and back＇ is a phrase that is often used to describe the two-way information flow in translational medicine. On one hand, scientists working at the bench make new discoveries that enable clinicians to revolutionize patient care, while on the other hand, clinical investigations at the bedside provide new knowledge about diseases, which stimulate basic research at the bench.

关键词：世界香港健康科学发现临床医生临床调查基础研究信息流

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Effects of Light on the Growth and Clonal Reproduction of Ligularia virgaurea

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Journal of Integrative Plant Biology 2008年第8期50卷 1015-1023页

作者： man-tang Wang Zhi-Gang Zhao Guo-Zhen Du Yan-Long He Key Laboratory of Arid and Grassland Agroecology under the Ministry of Education Lanzhou University Lanzhou 730000 China

Ligularia virgaurea is a perennial herb that is widely distributed in the alpine meadow on the eastern Qinghai-Tibet plateau. We investigated the patterns of growth and reproduction of L. virgaurea under two contrasting levels of light conditions for two continuous growing seasons. Our results showed that the light effects on the maximum relative growth rate, the shoot weight ratio and the root weight ratio differed between the two growing seasons. L. virgaurea reproduced initially through rhizome in the second growing season, rather than sexual reproduction. The proportion of genets with clonal reproduction decreased under shaded conditions. A minimum genet size should be attained for clonal reproduction to begin under the shaded conditions. There was a positive linear relationship between clonal reproduction and genet size. Light level affected the allocation of total biomass to clonal structures, with less allocation under the full natural irradiance than under the shaded conditions. There seemed to be a trade-off between vegetative growth and clonal reproduction under the full natural irradiance, in terms of smaller relative growth rates of genets with clonal reproduction than those without clonal reproduction. L. virgaurea emphasized clonal reproduction under the full natural irradiance, while the plant emphasized vegetative growth under the shaded conditions.

关键词： biomass allocation clonal reproduction Ligularia virgaurea relative growth rate threshold size

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Oncocytic adrenocortical tumor with uncertain malignant potential in pediatric population: A case report and review of literature

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World Journal of Clinical Cases 2021年第20期9卷 5675-5682页

作者： Xiao-Chun Chen Yun-man tang Yu Mao Dao-Rui Qin Department of Pediatric Surgery Sichuan Academy of Medical Sciences Sichuan Provincial People's HospitalChengdu 610072Sichuan ProvinceChina

BACKGROUND Oncocytic adrenocortical tumor(OACT)is rare,with few cases reported in the *** more than 20 cases in children have been *** clinical characteristics,diagnosis,treatment and prognosis of children with OACT are summarized based on a literature review,in order to improve the understanding of OACT in *** SUMMARY We report a case of a 17-mo-old patient who was admitted to our hospital due to symptoms of odynuria and fever,which are clinical features consistent with a functional adrenocortical *** patient was diagnosed with OACT of uncertain malignant *** tomography indicated a soft tissue giant tumor in the right adrenal region,approximately 4.3 cm×5.5 cm in *** nodular and speckled calcifications were observed in the *** patient received robot-assisted laparoscopic right adrenal tumor *** pathological results were consistent with OACT,and immunohistochemical results showed cytokeratin+/-,chromogranin A+,synaptophysin-,neuronspecific enolase-,S100-,Ki67 about 10%,CD34-and D2-40-.After surgery,urinary tract ultrasonography was reviewed monthly,catecholamine hormone and sex hormone levels were examined every 2 mo and computed tomography was performed every 6 *** date,no tumor metastasis or recurrence has been identified in this *** levels of sex hormones and catecholamine hormones decreased to normal 1 mo after *** OACT is rare in the pediatric population,with few cases reported in the *** most pediatric OACTs are benign,malignant cases have been *** resection is the preferred option in most patients.

关键词： Oncocytic adrenocortical tumor Adrenocortical tumor Robotic surgery Children Case report

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