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A possible hydrolysis mechanism of β-naphthyl acetate catalyzed by antibodies

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Cell Research 1998年第3期8卷 219-230页

作者： YUAN YU REN zong xiang xia CUI HONG YANG BING HUI YANG MING YEH(Shanghai Institute of Cell Biology, Chinese Academy of Sciences, China)(Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, China) Shanghai Institute of Cell Biology Chinese Academy of Sciences China

The mechanism of ester hydrolysis has been extensively studied; however, the precise function of active-site residues in promoting catalysis is nuclear. We describe here the structural models for the complex of a catalytic sntibody Fv fragment with a phosphonate transition -state analogue, constructed by using gene cloning, sequencing and molecular modeling, mainly based on a known X-ray structure of a catalytic atibody. Hydrophobic and electrostatic analyses of the Fv/analog and Fv/substrate interaction suggest the hydrolysis mechanism: In L91 and Tyr H97 play important roles to stabilize the β-naphthyl group of hapten through r-stack; His H35 donates a pair of free electrons at the atom NEZ to an active water and let it to be a partial hydroxide, which attacks the carbon atom of the carbonyl group of the substrate. Both His H35 and Arg L96 can form hydrogen bonds and stabilize the Anoinc tetrahedral intermediate formed during turnover. This mechanism emphasizes that an active water bridge may be formed during hydrolysis process.

关键词： Catalytic antibody gene cloning cDNA sequence molecular modeling ester hydrolysis mechanism

Prediction of antigenic determinants of trichosanthin by molecular modeling

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Cell Research 1996年第2期6卷 93-100页

作者： HE YONG NING zong xiang xia YIN WANG YONG YONG JI MING YEH (Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China)( Shanghai Institute of Cell Biology, Chinese Academy of Sciences, Shanghai 200031, China)(Corresp Shanghai Institute of Cell Biology Chinese Academy of Sciences Shanghai 200031 China

The antigenic determinants of trichosanthin were predicted by molecular modeling. First, the threedimensional structure model of the antigen-binding fragment of anti-trichosanthin immunoglobulin E was built on the basis of its amino-acid sequence and the known three-dimensional structure of an antibody with similar sequence. Secondly, the preferable antigen-antibody interactions were obtained based on the known three-dimensional structure of trichosanthin and of the hypervariable regions of anti-trichosanthin immunoglobulin E. Two regions in the molecular surface of trichosanthin were found to form extensive interactions with the hypervariable regions of the antibody and have been predicted to be the possible antigenic determinants: one is composed of two polypeptide segments, Ile201-Glu210 and Ile225-Asp229, which are close to each other in the three-dimensional structure; and the other is the segment Lys173-Thr178. The former region seems to be the more reasonable antigenic determinant than the latter one.

关键词： Antigenic determinants trichosanthin anti-trichosanthin immunoglobulin E molecular modeling

Observation of acoustic hybrid topological phases induced by the p-d orbital interactions

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 132-139页

作者： xiao xiang Feng Gao Yu-Gui Peng Peng Wu zong-Lin Li Xue-Feng Zhu School of Physics and Innovation Institute Huazhong University of Science and Technology

In spinless systems,growing attention has recently been attracted to synthetic gauge fields,which redefine the fundamental crystal symmetries by utilizing the projective algebraic ***,synthetic gauge fields have been commonly investigated in single orbital systems,and explorations on hybrid orbitals remain elusive in ***,we report the experimental observation of hybrid topological phases induced by hybrid synthetic gauge flux,which is formed by the interaction between p and d orbitals embedded in acoustic *** breaking the translation symmetries of Lxand/or Ly,we unambiguously demonstrate the first-order M?bius edge states and higher-order corner *** work establishes a platform for seeking exotic topological phases induced by hybrid-orbitals interactions and initializing the framework of hybrid-orbitalsrelated topological *** applications can be anticipated in scenarios such as high-quality sensing and robust wave trapping due to the stepwise energy distribution of the hybrid topological phase.

关键词： topological insulator synthetic gauge field projective symmetry corner states

Perilipin-2 mediates ferroptosis in oligodendrocyte progenitor cells and myelin injury after ischemic stroke

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Neural Regeneration Research 2025年第7期20卷 2015-2028页

作者： Jian Yang Jiang Wu Xueshun Xie Pengfei xia Jinxin Lu Jiale Liu Lei Bai xiang Li Zhengquan Yu Haiying Li Department of Neurosurgery&Brain and Nerve Research Laboratory The First Affiliated Hospital of Soochow UniversitySuzhouJiangsu ProvinceChina Institute of Stroke Research Soochow UniversitySuzhouJiangsu ProvinceChina

Differentiation of oligodendrocyte progenitor cells into mature myelin-forming oligodendrocytes contributes to *** of remyelination due to oligodendrocyte progenitor cell death can result in severe nerve *** is an iron-dependent form of regulated cell death caused by membrane rupture induced by lipid peroxidation,and plays an important role in the pathological process of ischemic ***,there are few studies on oligodendrocyte progenitor cell *** analyzed transcriptome sequencing data from GEO databases and identified a role of ferroptosis in oligodendrocyte progenitor cell death and myelin injury after cerebral *** analysis suggested that perilipin-2(PLIN2)was involved in oligodendrocyte progenitor cell ***2 is a lipid storage protein and a marker of hypoxia-sensitive lipid droplet *** further investigation,we established a mouse model of cerebral ischemia/*** found significant myelin damage after cerebral ischemia,as well as oligodendrocyte progenitor cell death and increased lipid peroxidation levels around the infarct *** ferroptosis inhibitor,ferrostatin-1,rescued oligodendrocyte progenitor cell death and subsequent myelin *** also found increased PLIN2 levels in the peri-infarct area that co-localized with oligodendrocyte progenitor ***2 knockdown rescued demyelination and improved neurological *** findings suggest that targeting PLIN2 to regulate oligodendrocyte progenitor cell ferroptosis may be a potential therapeutic strategy for rescuing myelin damage after cerebral ischemia.

关键词： bioinformatics bulk RNA sequencing ferroptosis ischemic stroke myelin injury oligodendrocyte progenitor cell perilipin-2 single-cell RNA sequencing

Visualization of the protective role of estrogen against female liver fibrosis via an ER viscosity NIR fluorescent probe

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Science China Chemistry 2025年第1期 360-368页

作者： Zheng Liu Changyu Zhang Zipeng Li Wanying Ma Jia Liu xiang xia Ning Xu Wen Sun Jianjun Du Jiangli Fan xiaojun Peng State Key Laboratory of Fine Chemicals Dalian University of Technology Ningbo Institute of Dalian University of Technology

Endoplasmic reticulum(ER) viscosity has emerged as a new potential biomarker for hepatic fibrosis(HF). Herein, we report the first ER-targeting viscosity-responsive near-infrared(NIR) fluorescent probe HBT-PP for investigations of HF *** twisted intramolecular charge transfer(TICT) and the excited state intramolecular proton transfer(ESIPT) are combined to endow HBT-PP with the selective response towards viscosity(～62-fold) and a super large stokes shift(～320 nm). HBT-PP mainly targets organelle ER and is able to image the drug-or alcohol-induced viscosity elevation in living cells. Significantly,HBT-PP was successfully applied to visualize the gender difference in HF and the protective role of estrogen in restraining HF progression. Of note, after 10 min of stain with HBT-PP, HF lesions showed a stage-based response, indicating the potential of this probe in fast and early diagnosis of HF. These results clearly demonstrated the promising application of HBT-PP as a new tool for exploring ER viscosity-involved physiological and pathological processes.

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我国当代体育教学原则体系研究综述

山东体育学院学报 2004年第1期20卷 93-95页

作者：崔宗祥赵晚霞曲阜师范大学体育科学学院山东曲阜273165

运用文献资料法对新中国成立以来我国体育理论界有关体育教学原则体系的主要成果进行综述,分析了该体系整体发展脉络、原因及其指导意义。认为现代体育教学原则体系应根据现代体育教学的特点、发展趋势从整体、综合的观念出发构建。

关键词：中国当代体育教学教学原则综述教学观念教材终身体育

Photonic band structure of one-dimensional metal/dielectric structures calculated by the plane-wave expansion method

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Science China(Physics,Mechanics & Astronomy) 2015年第7期58卷 84-89页

作者： zong YiXin xia JianBai The State Key Laboratory of Superlattices and Microstructures Institute of Semiconductors Chinese Academy of Sciences

The plane-wave expansion(PWE) method is employed to calculate the photonic band structures of metal/dielectric(M/D) periodic systems. We consider a one-dimensional(1D) M/D superlattice with a metal layer characterized by a frequency-dependent dielectric function. To calculate the photonic band of such a system, we propose a new method and thus avoid solving the nonlinear eigenvalue equations. We obtained the frequency dispersions and the energy distributions of eigen-modes of 1D superlattices. This general method is applicable to calculate the photonic band of a broad class of physical systems, e.g. 2D and 3D M/D photonic crystals. For comparison, we present a simple introduction of the finite-difference(FD) method to calculate the same system, and the agreement turns out to be good. But the FD method cannot be applied to the TM modes of the M/D superlattice.

关键词： photonic crystal PWE method frequency dispersion energy distribution

Anticipative Stochastic Differential Equations with Non-smooth Diffusion Coefficient

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Acta Mathematica Sinica,English Series 2006年第5期22卷 1473-1480页

作者： zong xia LIANG Department of Mathematical Sciences Tsinghua University Beijing 100084 P. R. China

In this paper we prove the existence and uniqueness of the solutions to the one-dimensional linear stochastic differential equation with Skorohod integral Xt（ω）=η（w）＋∫^t 0 asXs（ω）dWs＋∫^t 0 bsXs（ω）ds, t∈[0,1] where （Ws） is the canonical Wiener process defined on the standard Wiener space （W,H,u）, a is non-smooth and adapted, but η and b may be anticipating to the filtration generated by （Ws）. The intention of the paper is to eliminate the regularity of the diffusion coefficient a in the Malliavin sense, in the existing literature. The idea is to approach the non-smooth diffusion coefficient a by smooth ones.

关键词： Non-smooth and anticipative stochastic differential equations Skorohod integral Malliavin derivative

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BES端盖簇射计数器模型的束流测试

高能物理与核物理 1987年第3期 321-326页

作者：王曼李金夏小米崔象宗赖元芬姚小光中国科学院高能物理研究所

研制并测试了一台铅板和自猝灭流光管夹层式的气体取样簇射计数器.计数管使用了铝方管和阳极丝读出.能量分辨σ/E在E_e=1GeV时达15.5％,能量响应范围是0—2GeV.本文描述了束流测试的方法和计数器模型的各种性能.

关键词：计数器模型北京谱仪簇射计数器辐射计数器束流电流能量响应 BES