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Separation mechanism of chiral compounds in chiral stationary phase liquid chromatography

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Chinese Journal of Chemistry 1991年第3期9卷 231-236页

作者： zou,han-fa zhang,yu-kui lu,pei-chang dalian chromatographic r.& d.center of china dalian Institute of Chemical Physics,Academia Sinica,dalian 116011 dalian chromatographic r.& d.center of china dalian Institute of Chemical Physics Academia Sinica Dalian 116011

In this paper,the concept of reversed-or normal-phase chiral stationary phase liquid chromatography has been put forward according to the polar strength of mobile and stationary phases. The statistical model developed in HPLC has been used to investigate the separation mechanism of d-and L-enantiomer in chiral stationary phase liquid *** has been observed that the variation of capacity factor of enantiomers with mobile phase composition in both reversed-phase and normal-phase chiral stationary phase liquid chromatography can be described by the fundamental elution equation lnk'=a+blnC_b+cC_*** effect of mobile phase composition on the selec- tivity of enantiomers d and L in normal-phase chiral stationary phase liquid chromatography cam be described by the equation lnα=⊿a+⊿blnC_b,but in reversed-phase chiral stationary phase liquid chromatography the selectivity is almost independant of the mobile phase composition.

关键词： Separation mechanism of chiral compounds in chiral stationary phase liquid chromatography

Expert systems for HPLC in biochemistry—The knowledge base for selection of HPLC column system in the separation of amino acids, peptides and proteins

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Chinese Journal of Chemistry 1991年第5期9卷 441-447页

作者： zhang yu-kui zou han-fa lu pei-zhang YAO Zhi-Jian dalian chromatographic r.&d.center of china Dalian nstitute of Chemical PhysicsAcademia SinicaDalian 116011 Laboratory of Protein Chemistry and Biotechnology Institute of Basic Medical SciencesBeijing 100850

The strategy of expert system for high performance liquid chromatography was discussed, the attentions are mainly placed on the knowledge base for selection of column system, separation modes and detection modes in th... 详细信息

关键词： The knowledge base for selection of HPLC column system in the separation of amino acids Expert systems for HPLC in biochemistry peptides and proteins base HPLC

The principle of optimization of binary mobile phase composition of multi-step linear gradient elution

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Acta Chimica Sinica English Edition 1989年第6期7卷 511-519页

作者： zou han-fa zhang yu-kui dONG Li-Fu BAO Mian-Sheng lu pei-zhang dalian Institute of Chemical Physics Academia SinicaDalian Chromatographic R&D Center of ChinaDalian

The basic principle of optimal method called “moving overlapping resolution mapping Method” to select the optimal binary mobile phase composition of multi-step linear gradient liquid chromatography is discussed with simultaneously considering effects of position of solute inside the column and mobile phase composition on peak resolution and retention value, then a BASIC program based on this principle is developed in IBM-PC computer. The validities of both principle of optimization and BASIC program are confirmed by separation of samples Containing bile acids and PAHs in rP-HPLC.

关键词： time length The principle of optimization of binary mobile phase composition of multi-step linear gradient elution

Plasma transport simulation under different conditions and optimization analysis of dual-stage grid ion thruster

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Chinese Journal of Aeronautics 2023年第7期36卷 388-399页

作者： Yajie han Guangqing XIA Bin SUN chang lu Junjun zhang Vladimir A.SAETCHNIKOV State Key Laboratory of Structural Analysis Optimization and CAE Software for Industrial EquipmentDalian University of TechnologyDalian 116024China Key Laboratory of Advanced Technology for Aerospace Vehicles of Liaoning Province Dalian University of TechnologyDalian 116024China Collaborative Innovation center of Micr.&Nano Satellites of Hebei Province North China Institute of Aerospace EngineeringLangfang 065000China Physics and Aerospace Technology department Belarusian State UniversityMinsk 220030Belarus

In order to study the extraction and acceleration mechanism of the dual-stage grid,a three-dimensional model based on the Particle-In-Cell/Monte Carlo Collision(PIC/MCC)method is ***-stage grid ion thruster is a new type of electrostatic ion thruster,which can break through the limitations of traditional gridded ion thrusters,and greatly improve the specific *** high performance also makes the grid sensitive to operating *** this paper,the influence of grid parameters on xenon ion thruster’s performance in a wide range is systematically simulated,and the optimal operating condition is *** the over-focusing of the plume,and the transparency of the screen grid are improved,and the grid corrosion is reduced through simulation *** specific impulse under the given working conditions is 9877.24 s and the thrust is 7.28 *** on the simulation optimization,the limitation of the dual-stage grid is *** grid performs well under high voltage conditions(>3000 V)but not well under low voltage conditions(rgon is cheaper and more advantageous in future engineering applications,the plasma distribution and grid extraction ability under xenon and argon are analyzed and compared to study the flexibility of the dual-stage grid ion *** simulation results show that a set of optimal parameters is only applicable to the corresponding propellant,which needs to be optimized for different propellant types.

关键词： 3d modeling dual-stage grid Ion thruster PIC/MCC method Plasma simulation

Confinement characteristic of primary electrons with the variation of channel width in the discharge chamber of annular ion thruster

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Chinese Journal of Aeronautics 2021年第5期34卷 79-92页

作者： chang lu Guangqing XIA Bin SUN Yajie han State Key Laboratory of Structural Analysis for Industrial Equipment Dalian University of TechnologyDalian 116024China Key Laboratory of Advanced Technology for Aerospace Vehicles of Liaoning Province Dalian University of TechnologyDalian 116024China

In this paper,the confinement characteristic of primary electrons in the non-axisymmetric discharge chamber of annular ion thruster is investigated by a three-dimensional(3 d)non-self-consistent particle tracking model with Monte Carlo Collision(MCC)*** results show that:The density of primary electrons upstream of ion optics on cathode axis is about 5–50 times higher than that of the other side,which means that the density of primary electrons is obviously *** channel width has a significant effect on the average density and uniformity of primary *** average density can be increased by nearly 1.5 times under the appropriate channel width,meanwhile,the variance of density distribution can be reduced by more than 2 *** is because that increasing the channel width can improve the average confinement length of primary electrons ***,there is an infection point in the increase of primary electron average confinement length with the channel width,which caused by the significant change of magnetic field *** the case after the inflection point,primary electron mainly(more than 50%)moves to the channel center,which makes the average confinement length of primary electrons and their number in the discharge chamber increase largely.

关键词： Annular ion thruster Average confinement length Electric propulsion Ion thruster Primary electrons

Biological Fingerprinting Analysis of Interaction Between Taxoids in Taxus and Microtubule Protein by Microdialysis Coupled with High-performance Liquid Chromatography/Mass Spectrometry for Screening Antimicrotubule Agents

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Chemical research in Chinese Universities 2008年第4期24卷 411-419页

作者： LEI Xiao-yuan KONG Liang SU Xing-ye GUO Ming zou han-fa National chromatographic r＆A center Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian 116023 P. R. China College of Marine Environmental Engineering Dalian Fisheries University Dalian 116023 P R. China department of Chemistry and Chemical Technology Dalian University Dalian 116622 P. R. China

Some natural products, such as traditional Chinese medicines（TCMs）, contain compounds with anticancer activity and have attracted a great interest in recent years as alternative anticancer therapies. A quick and convenient assay for screening antimicrotubule compounds in which in vitro microdialysis/high-performance liquid chromatography （HPLC） is used to monitor the binding of the compounds extracted from TCM Taxus cuspidata Siebold ＆ Zucc（Taxus） to microtubules is reported. It was observed that the extract of Taxus contains at least five compounds which have affinity interaction with microtubules by biological fingerprinting analysis, and they were identified as the taxoids of taxol, baccatin III, 10-deacetylbaccatin Ⅲ（10-dAB）, cephalomannine and 7-epi-10-deacetyltaxol （7-epi-10-dAT） based on the comparison of their high-performance liquid chromatographic/mass spectrometric and UV spectra with those of the standard samples, both assembly-promoting and disassembly-inhibiting characteristics of those compounds were evaluated. It was observed that baccatin Ⅲ and 10-dAB bound to microtubules and the binding degrees were influenced by GTP. Competitive binding behavior of taxol with other four taxoids to microtubules was also investigated.

关键词： Microdialysis/high-performance liquid chromatography(HPLC) Biological fingerprinting analysis Taxoids Microtubule Taxus

FP-Zernike:An Open-source Structural database Construction Toolkit for fast Structure retrieval

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Genomics, Proteomics & Bioinformatics 2024年第1期22卷 111-119页

作者： Junhai Qi Chenjie Feng yulin Shi Jianyi Yang fa zhang Guojun Li renmin han research center for Mathematics and Interdisciplinary Sciences Shandong UniversityQingdao 266237China BioMap research Menlo ParkCA 94025USA College of Medical Information and Engineering Ningxia Medical UniversityYinchuan 750004China Institute of Engineering Medicine Beijing Institute of TechnologyBeijing 100081China

The release of AlphaFold2 has sparked a rapid expansion in protein model *** protein structure retrieval is crucial for the analysis of structure models,while measuring the similarity between structures is the key challenge in structural *** existing structure alignment algorithms can address this challenge,they are often ***,the state-of-the-art approach involves converting protein structures into three-dimensional(3d)Zernike descriptors and assessing similarity using Euclidean ***,the methods for computing 3d Zernike descriptors mainly rely on structural surfaces and are predominantly web-based,thus limiting their application in studying custom *** overcome this limitation,we developed FP-Zernike,a user-friendly toolkit for computing different types of Zernike descriptors based on feature *** simply need to enter a single line of command to calculate the Zernike descriptors of all structures in customized ***-Zernike outperforms the leading method in terms of retrieval accuracy and binary classification accuracy across diverse benchmark *** addition,we showed the application of FP-Zernike in the construction of the descriptor database and the protocol used for the Protein data Bank(PdB)dataset to facilitate the local deployment of this tool for interested *** demonstration contained 590,685 structures,and at this scale,our system required only 4-9 s to complete a *** experiments confirmed that it achieved the state-of-the-art accuracy ***-Zernike is an open-source toolkit,with the source code and related data accessible at https://***/biocode/tools/BT007365/releases/0.1,as well as through a webserver at http://***/.

关键词： Zernike descriptor Structure alignment PdB dataset Open-source retrieval system

Human neural stem cell-derived extracellular vesicles protect against ischemic stroke by activating the PI3K/AKT/mTOr pathway

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Neural regeneration research 2025年第11期20卷 3245-3258页

作者： Jiayi Wang Mengke Zhao dong Fu Meina Wang Chao han Zhongyue Lv Liang Wang Jing Liu Stem Cell Clinical research center The First Affiliated Hospital of Dalian Medical UniversityDalianLiaoning ProvinceChina dalian Innovation Institute of Stem Cell and Precision Medicine DalianLiaoning ProvinceChina Institute(College)of Integrative Medicine Dalian Medical UniversityDalianLiaoning ProvinceChina

Human neural stem cell-derived extracellular vesicles exhibit analogous functions to their parental cells,and can thus be used as substitutes for stem cells in stem cell therapy,thereby mitigating the risks of stem cell therapy and advancing the frontiers of stem cell-derived *** lays a foundation for the development of potentially potent new treatment modalities for ischemic ***,the precise mechanisms underlying the efficacy and safety of human neural stem cell-derived extracellular vesicles remain unclear,presenting challenges for clinical *** promote the translation of therapy based on human neural stem cell-derived extracellular vesicles from the bench to the bedside,we conducted a comprehensive preclinical study to evaluate the efficacy and safety of human neural stem cell-derived extracellular vesicles in the treatment of ischemic *** found that administration of human neural stem cell-derived extracellular vesicles to an ischemic stroke rat model reduced the volume of cerebral infarction and promoted functional recovery by alleviating neuronal *** human neural stem cell-derived extracellular vesicles reduced neuronal apoptosis by enhancing phosphorylation of phosphoinositide 3-kinase,mammalian target of rapamycin,and protein kinase B,and these effects were reversed by treatment with a phosphoinositide 3-kinase *** findings suggest that human neural stem cell-derived extracellular vesicles play a neuroprotective role in ischemic stroke through activation of phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin signaling ***,we showed that human neural stem cell-derived extracellular vesicles have a good in vivo safety ***,human neural stem cell-derived extracellular vesicles are a promising potential agent for the treatment of ischemic stroke.

关键词： behavior exosome extracellular vesicles ischemic stroke mammalian target of rapamycin(mTOr) middle cerebral artery occlusion neural stem cells neuronal apoptosis phosphoinositide 3-kinase(PI3K) protein kinase B(AKT)

Insight into the dual Cycle Mechanism of Methanol-to-OIefins reaction over SAPO-34 Molecular Sieve by Isotopic Tracer Studies

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Chemical research in Chinese Universities 2020年第6期36卷 1203-1208页

作者： yu Bowen LOU Caiyi zhang Wenna XU Shutao han Jingfeng yu Zhengxi WEI Yingxu LIU Zhongmin National Engineering Laboratory for Methanol to Olefins Dalian National Laboratory for Clean EnergyiChEM(Collaborative Innovation Center of Chemistry for Energy Materials)Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023P.R.China University of Chinese Academy of Sciences Beijing 100039P.R.China

Methanol-to-olefins(MTO)reaction is one of the important non-petroleum routes to produce light olefinsover acidic molecular *** this study,the complete reaction course of MTO on SAPO-34 molecular sieve with retained organics evolution from induction period to deactivation period was investigated systematically at different weight hourly space velocities(WHSV)of *** the aid of 12C/3C-methanol isotopic switch experiment,the dual cycle mechanism involving aromatics-based cycle and alkenes-based cycle was evaluated during the whole reac-tion *** detailed reaction route varied with the evolution of the retained organics in the catalyst at different reaction *** aromatics-based cycle and alkenes-based cycle alternately dominate the reaction *** the efficient reaction period,aromatics-based cvcle is the main reaction mechanism,while in the induction and deactiva-tion *** contribution of alkenes-based cvcle mechanism will become more important.

关键词： SAPO-34 Methanol-to-olefin(MTO) Polymethy Ibenzene dual-cycle mechanism Isotopic tracer