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Affinity-guided protein conjugation: the trilogy of covalent protein labeling, assembly and inhibition

Science China Chemistry 2016年第7期59卷 853-861页

作者： Yongsheng yu Jiang xia Center of Novel Biomaterials Department of Chemistry Chinese University of Hong Kong

Specific and dynamic biological interactions pave the blueprint of signal networks in cell. For example, a great variety of specific protein-ligand interactions define how intracellular signals flow. Taking advantage of the specificity of these interactions, we postulate an "affinity-guided covalent conjugation" strategy to lock binding ligands through covalent reactions between the ligand and the receptor protein. The presence of a nucleophile close to the ligand binding site of a protein is sine qua none of this reaction. Specific noncovalent interaction of a ligand derivative(which contains an electrophile at a designed position) to the ligand binding site of the protein brings the electrophile to the close proximity of the nucleophile. Subsequently, a conjugation reaction spontaneously takes place between the nucleophile and the electrophile, and leads to an intermolecular covalent linkage. This strategy was first showcased in coiled coil peptides which include a cysteine mutation at a selected position. The short peptide sequence was used for covalent labeling of cell surface receptors. The same strategy was then used to guide the design of a set of protein Lego bricks for covalent assembly of protein complexes of unnatural geometry. We finally made "reactive peptides" for natural adaptor proteins that play significant roles in signal transduction. The peptides were designed to react with a single domain of the multidomain adaptor protein, delivered into the cytosol of neurons, and re-directed the intracellular signal of neuronal migration. The trilogy of protein labeling, assembly, and inhibition of intracellular signals, all through a specific covalent bond, fully demonstrated the generality and versatility of "affinity-guided covalent conjugation" in various applications.

关键词： peptide-peptide interaction covalent labeling bioconjugation reaction protein assembly inhibitor signal transduction affinity-guided reaction

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A Hybrid Procedure for Finding Real Points on a Real Algebraic Set

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Journal of Systems Science & Complexity 2019年第1期32卷 185-204页

作者： WANG yu xia Bican LMAM & School of Mathematical Sciences Peking University

Motivated by the idea of Shen, et al.'s work, which proposed a hybrid procedure for real root isolation of polynomial equations based on homotopy continuation methods and interval analysis,this paper presents a hybrid procedure to compute sample points on each connected component of a real algebraic set by combining a special homotopy method and interval analysis with a better estimate on initial intervals. For a real algebraic set given by a polynomial system, the new method ?rst constructs a square polynomial system which represents the sample points, and then solve this system by a special homotopy continuation method introduced recently by Wang, et al.(2017). For each root returned by the homotopy continuation method, which is a complex approximation of some(complex/real) root of the polynomial system, interval analysis is used to verify whether it is an approximation of a real root and ?nally get real points on the given real algebraic set. A new estimate on initial intervals is presented which helps compute smaller initial intervals before performing interval iteration and thus saves computation. Experiments show that the new method works pretty well on tested examples.

关键词： Homotopy continuation interval arithmetic polynomial system real variety

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Low-temperature and flexible strategy to in-situ fabricate ZrSiO_(4)-based ceramic composites via doping and tuning solid-state reaction

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Journal of Advanced Ceramics 2023年第6期12卷 1238-1257页

作者： Bohan Wang Le fu Junjie Song Wenjun yu Ying Deng Guofu Xu Jiwu Huang Wei xia School of Materials Science and Engineering Central South UniversityChangsha 410083China State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China Shandong Laboratory of Yantai Advanced Materials and Green Manufacturing Yantai 264006China Applied Materials Science Department of Materials Science and EngineeringUppsala UniversityUppsala 75121Sweden

Synthetic zircon(ZrSiO_(4))ceramics are typically fabricated at elevated temperatures(over 1500℃),which would lead to high manufacturing ***,reports about preparing ZrSiO_(4)-based ceramic composites via controlling the solid-state reaction between zirconia(ZrO_(2))and silica(SiO_(2))are *** this work,we proposed a low-temperature strategy to flexibly design and fabricate ZrSiO_(4)-based ceramic composites via doping and tuning the solid-state *** ceramic composites and ZrSiO_(4) ceramics were in-situ prepared by reactive fast hot pressing(FHP)at approximately 1250℃ based on the proposed strategy,i.e.,a ZrSiO_(4)-SiO_(2) dual-phase composite with bicontinuous interpenetrating and hierarchical microstructures,a ZrSiO_(4)-ZrO_(2) dual-phase composite with a microstructure of ZrO_(2) submicron-and nano-particles embedded in a micron ZrSiO_(4) matrix,and ZrSiO_(4) ceramics with a small amount of residual ZrO_(2) *** results showed that the phase compositions,microstructure configurations,mechanical properties,and wear resistance of the materials can be flexibly regulated by the proposed ***,ZrSiO_(4)-based ceramic composites with different properties can be easily fabricated based on different application *** findings would offer useful guidance for researchers to flexibly fabricate ZrSiO_(4)-based ceramic composites at low temperatures and tailor their microstructures and properties through doping and tuning the solid-state reaction.

关键词： zirconia(ZrO_(2))-silica(SiO_(2)) zircon(ZrSiO_(4)) solid-state reaction ceramic composite mechanical properties wear resistance

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Enhancing security of NVM-based main memory with dynamic Feistel network mapping

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Frontiers of Information Technology & Electronic Engineering 2018年第7期19卷 847-863页

作者： Fang-ting HUANG Dan FENG Wen xia Wen ZHOU yu-cheng ZHANG Min fu Chun-tao JIANG yu-kun ZHOU Wuhan National Laboratory for Optoelectronics Wuhan 430074 China MOE Key Laboratory of Information Storage System Wuhan 430074 China School of Computer Science and Technology Huazhong University of Science and Technology Wuhan 430074 China

As promising alternatives in building future main memory systems, emerging non-volatile memory(NVM) technologies can increase memory capacity in a cost-effective and power-efficient way. However, NVM is facing security threats due to its limited write endurance: a malicious adversary can wear out the cells and cause the NVM system to fail quickly. To address this issue, several wear-leveling schemes have been proposed to evenly distribute write traffic in a security-aware manner. In this study, we present a new type of timing attack, remapping timing attack(RTA), based on information leakage from the remapping latency difference in NVM. Our analysis and experimental results show that RTA can cause three of the latest wear-leveling schemes(i.e., region-based start-gap,security refresh, and multi-way wear leveling) to lose their effectiveness in several days(even minutes), causing failure of NVM. To defend against such an attack, we further propose a novel wear-leveling scheme called the ‘security region-based start-gap(security RBSG)', which is a two-stage strategy using a dynamic Feistel network to enhance the simple start-gap wear leveling with level-adjustable security assurance. The theoretical analysis and evaluation results show that the proposed security RBSG not only performs well when facing traditional malicious attacks, but also better defends against RTA.

关键词： Non-volatile memory (NVM) Endurance Wear leveling Timing attack

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Coupled trace element and SIMS sulfur isotope geochemistry of sedimentary pyrite:Implications on pyrite growth of Caixiashan Pb-Zn deposit

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Geoscience Frontiers 2019年第6期10卷 2177-2188页

作者： Dengfeng Li Huayong Chen xiaoming Sun yu fu Qiaofen Liu xiaoping xia Qing Yang School of Marine Sciences Sun Yat-sen UniversityGuangzhou510006China Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering Guangzhou510006China Key Laboratory of Mineralogy and Metallogeny Chinese Academy of SciencesGuangzhou510640China School of Earth Science and Engineering Sun Yat-sen UniversityGuangzhou510275China State Key Laboratory of Isotope Geochemistry Guangzhou Institute of GeochemistryChinese Academy of SciencesGuangzhou510604China

Colloform pyrite with core-rim texture is commonly deposited in carbonate platforms associated with the sulfide ores such as the Caixiashan Pb-Zn ***,the genesis of colloform pyrite in Pb-Zn deposits,its growth controls and their geological implication are insufficiently *** of in-situ trace element and SIMS sulfur isotopes has revealed geochemical variations among these pyrite *** colloform pyrite occur as residual phases of core-rim aggregates,the cores are made up of very fine-grained anhedral pyrite particles,with some rims being made up of fine-grained and poorlycrystallized pyrite,while the other rims were featured with euhedral cubic *** are cemented by fine-grained calcite and/or dolomite with minor *** isotope analysis shows that some wellpreserved rims have negative δ^34 S values(-28.12‰to-0.49‰),whereas most of the cores and rims have positive δ^34 S values(>0 to+44.28‰;peak at+14.91‰).Integrating with the methane and sulfate were observed in previous fluid inclusion study,we suggest that the 34 S depleted rims were initially formed by bacteria sulfate reduction(BSR),whereas the positive δ^34 S values were resulted from the sulfate reduction driven by anaerobic methane oxidation(AOM).The well-developed authigenic pyrite and calcite may also support the reaction of *** with petrographic observations,trace element composition of the colloform pyrite reveals the incorporation and precipitation behavior of those high abundance elements in the pyrite:Pb and Zn were present as mineral inclusion and likely precipitated before Fe,as supported by the time-resolved Pb-Zn signal spikes in most of the analyzed pyrite *** metals,such as Hg,Co and Ni,may have migrated as chloride complexes and entered the pyrite *** and Sb,generally influenced by complex-forming reactions rather than substitution ones,could also enter the pyrite lattice,or slightly predate the precipitation of coll

关键词： Pyrite trace elements SIMS sulfur isotopes Colloform pyrite Bacteria sulfate reduction(BSR) Anaerobic methane oxidation(AOM)

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Synthesis and Complexation Properties of Novel Biscalixarene Composed of Calix[4]arene and Thiacalix[4]arene Subunits

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Chinese Chemical Letters 2006年第8期17卷 1029-1032页

作者： Fa fu YANG xia ZHAO Cui yu HUANG Hong yu GUO Si Ning ZHENG Qi PENG College of Chemistry and Materials Fujian Normal University Fuzhou 350007 State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of Matter China Academy of Science Fuzhou 350002

The first example of biscalixarene composed of calix[4]arene and thiacalix[4]arene subunits 3 was facilely synthesized and showed good complexation properties for metal cations and zwitterionic α-amino acids.

关键词： Biscalixarene thiacalixarene complexation cation amino acid.

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Multiconstraint adaptive three-dimensional guidance law using convex optimization

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Journal of Systems Engineering and Electronics 2020年第4期31卷 791-803页

作者： fu Shengnan LIU xiaodong ZHANG Wenjie xia Qunli School of Mechatronical Engineering Beijing Institute of TechnologyBeijing 100081China Beijing Aerospace Automatic Control Institute Beijing 100854China School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China

The traditional guidance law only guarantees the accuracy of attacking a target. However, the look angle and acceleration constraints are indispensable in applications. A new adaptive three-dimensional proportional navigation(PN) guidance law is proposed based on convex optimization. Decomposition of the three-dimensional space is carried out to establish threedimensional kinematic engagements. The constraints and the performance index are disposed by using the convex optimization method. PN guidance gains can be obtained by solving the optimization problem. This solution is more rapid and programmatic than the traditional method and provides a foundation for future online guidance methods, which is of great value for engineering applications.

关键词： proportional navigation(PN) adaptive guidance law three-dimensional space second-order cone programming(SOCP) convex optimal control

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Bioprinting and in vitro characterization of alginate dialdehyde-gelatin hydrogel bio‑ink

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Bio-Design and Manufacturing 2020年第1期3卷 48-59页

作者： fu You xia Wu Michael Kelly Xiongbiao Chen Division of Biomedical Engineering College of EngineeringUniversity of SaskatchewanSaskatoonSK S7N 5A9Canada Department of Neurosurgery College of MedicineUniversity of SaskatchewanSaskatoonSK S7N 5A9Canada Department of Mechanical Engineering College of EngineeringUniversity of SaskatchewanSaskatoonSK S7N 5A9Canada

Cell-laden cardiac patches have recently been emerging to renew cellular sources for myocardial infarction(MI,commonly know as a heart attack)***,the fabrication of cell-laden patches with porous structure remains challenging due to the limitations of currently available hydrogels and existing processing *** present study utilized a bioprinting technique to fabricate hydrogel patches and characterize them in terms of printability,mechanical and biological ***-laden hydrogel(or bio-ink)was formulated from alginate dialdehyde(ADA)and gelatin(GEL)to improve the printability,degradability as well as *** groups of hydrogel compositions were designed to investigate the influence of the oxidation degree of ADA and hydrogels concentration on the properties of printed ***-GEL hydrogels have generally shown favorable for living cells(***926 cells and hybrid human umbilical vein endothelial cell line).The hydrogel with an oxidation degree of 10%and a concentration ratio of 70/30(or 10%ADA70-GEL30)demonstrated the best printability among the groups *** hydrogels were also bioprinted with the living cells(***926),and the scaffolds printed were then subject to the cell culture for 7 *** results illustrate that the scaffolds bioprinted from 10%ADA70–GEL30 hydrogels had the best homogenous cell distribution and also the highest cell *** together,in the present study we synthesized a newly formulated bio-ink from ADA and GEL and for the fist time,used them to bioprint cardiac patches,which have the potential to be used in MI repair.

关键词： Bioprinting Alginate dialdehyde Gelatin Bio-ink

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An impact angle constraint integral sliding mode guidance law for maneuvering targets interception

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Journal of Systems Engineering and Electronics 2020年第1期31卷 168-184页

作者： ZHANG Wenjie fu Shengnan LI Wei xia Qunli School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China School of Mechatronical Engineering Beijing Institute of TechnologyBeijing 100081China

An integral sliding mode guidance law(ISMGL)combined with the advantages of the integral sliding mode control(SMC)method is designed to address maneuvering target interception problems with impact angle *** relative motion equation of the missile and the target considering the impact angle constraint is established in the longitudinal plane,and an integral sliding mode surface is *** proposed guidance law resolves the existence of a steady-state error problem in the traditional *** a guidance law ensures that the missile hits the target with an ideal impact angle in finite time and the missile is kept highly robust throughout the interception *** adopting the dynamic surface control method,the ISMGL is designed considering the impact angle constraints and the autopilot dynamic *** to the Lyapunov stability theorem,all states of the closed-loop system are finally proven to be uniformly *** results are compared with the general sliding mode guidance law and the trajectory shaping guidance law,and the findings verify the effectiveness and superiority of the ISMGL.

关键词： impact angle constraint integral sliding mode maneuvering target Lyapunov stability dynamic characteristic

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Journal of Hydrodynamics 2021年第4期33卷 782-786页

作者： Jiang-hua Li yu-xian xia xiang Qiu yue-hong Qian Jia-hua Li yuan fu Shanghai Institute of Applied Mathematics and Mechanics School of Mechanics and Engineering ScienceShanghai UniversityShanghai200072China School of Mechanical Engineering Shanghai Institute of TechnologyShanghai201418China School of Science Shanghai Institute of TechnologyShanghai201418China School of Mathematical Sciences Soochow UniversitySuzhou215006China College of Urban Construction and Safety Engineering Shanghai Institute of TechnologyShanghai201418China

In this paper, Liutex similarity is extended and revised in channel turbulence. Liutex similarity is free from viscous dissipation, relaxing the very high Reynolds number assumption of K41. Liutex similarity hypothesis in 2-D channel turbulence is first proposed and estimated, which denotes that the statistical properties of Liutex field are uniquely and universally determined by the scale l, Liutex vortex number density n(A) with each area A and mean dissipation rate of square of Liutex magnitude ηL. The Liutex spectrum is EL (k) ∼ C[n(A)1/2ηL]1/3k−5/3 in the inertial range where energy spectrum exhibits double cascades. The scaling behaviors of Liutex spectrum in 2-D are independent of Reynolds number. Liutex structure functions are defined as Liutexp (l) ≡ 〈[δR∥(l)]p〉 which are in dependent of scales. It is found that Liutexp (l) ∼ C′(ηL)p/3l0 by dimensional analysis.

关键词： Liutex similarity energy spectrum 2-D turbulence

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