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Self-assembly behavior of phenyl modified β-cyclodextrins

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Science China Chemistry 2006年第3期49卷 230-237页

The self-assembly behavior of mono(6-phenolic-6-deoxy)-β-cyclodextrin bothin solution and the solid state is comparatively studied by X-ray crystallography and ~1H NMRspectroscopy. The results obtained show that the phenolic groups in the crystal 1 can successivelypenetrate into the adjacent β-cyclodextrin cavities from the secondary side to form head-to-taillinear polymeric su-pramolecule with a 2-fold screw axis. The self-assembly behavior also can bedetermined in D_2O solution, giving a self-association constant of 240 mol^(-1)·L. Using thepresent and previous structures reported for the relevant β-cyclodextrin derivatives, i.e.,mono(6-anilino-6-deoxy)-β-cyclodextrin, mono(6-phenylselenyl-6-deoxy)-β-cyclodextrin, andmono(6-phenylthio-6-deoxy)-β-cyclodextrin, we further reveal the factors governing the formationsof supramolecular assemblies.

关键词： crystal structure, cyclodextrin, pivot atoms, self-assembly, supramolecule.

Integral sliding mode control of time-delay systems with mismatching uncertainties

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Journal of Systems Engineering and Electronics 2010年第2期21卷 273-280页

作者： Fu zhao yu liu Xiuming Yao Baoku Su Space Control and Inertial Technology Research Center Harbin Institute of Technology Harbin 150001 R R. China

A linear matrix inequality （LMI）-based sliding surface design method for integral sliding mode control of uncertain time- delay systems with mismatching uncertainties is proposed. The uncertain time-delay system under consideration may have mis- matching norm bounded uncertainties in the state matrix as well as the input matrix, A sufficient condition for the existence of a sliding surface is given to guarantee asymptotic stability of the full order slJdJng mode dynamics. An LMI characterization of the slid- ing surface is given, together with an integral sliding mode control law guaranteeing the existence of a sliding mode from the initial time. Finally, a simulation is given to show the effectiveness of the proposed method.

关键词： linear matrix inequality integral sliding mode control uncertain time-delay systems mismatching uncertainties.

Experimental study on shear behavior of reinforced concrete beams with web horizontal reinforcement

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Frontiers of Structural and Civil Engineering 2014年第4期8卷 325-336页

作者： Dong XU yu zhao Chao liu Department of Bridge Engineering Tongji University Shanghai 200092 China

In determining the shear capacity of reinforced concrete beams, current codes do not provide any calculation method to evaluate the influence of web horizontal reinforcement, although they exist as structural reinforcements （or skin reinforcement）. The present paper comprises results of 11 reinforced concrete beams in an effort to investigate the influence of web horizontal reinforcement on the shear behavior of reinforced concrete beams. The primary design variables are the shear-span-depth ratio, different reinforcement ratio of stirrups and web horizontal reinforcement. Influence of web horizontal reinforcement on crack patterns and failure mode was studied. It was found that web horizontal reinforcement can increase the shear capacity of the beams and restrain growth of inclined cracks effectively. Test results are very valuable, as very few references of shear tests can be found focusing on the effect of web horizontal reinforcement on the shear capacity of the beams.

关键词： reinforced concrete beam shear strength web horizontal reinforcement experiments

Synthesis and Crystal Structure of 4,4′-Diamino-N,N′-diethyl Bisbenzenesulfamide

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Chinese Journal of Structural Chemistry 2007年第2期26卷 177-183页

作者： WANG Li-Min PAN Xiao-Juan FAN zhao-yu YANG liu-Bo liu Lian TIAN He Laboratory for Advanced Materials Institute of Fine ChemicalsEast China University of Science and Technology Shanghai 200237 China

A new compound of 4,4＇-diamino-N,V＇-diethyl bisbenzenesulfamide （C18H26N4O4S2, Fw = 426.55） has been synthesized and its structure was determined by X-ray crystallography method. The crystal belongs to the monoclinic system, space group P21/c with a = 10.0623（9）, b = 13.6759（13）, c =15.5309（14） A, β = 100.482（2）°, V= 2101.6（3） A^3, Dc = 1.348 g/cm^3, F（000） = 904, μ = 0.285 mm^-1, Z = 4, the final R = 0.0512 and wR = 0.1363 for 3485 observed reflections with I 〉 2σ（I）. The structure of the title compound is pseudo secondary axisymmetric, and the two sulfamide-groups show distorted tetrahedral configurations.

关键词： 4,4'-diamino-N,V'-diethyl bisbenzenesulfamide synthesis crystal structure

Ezetimibe Protects Endothelial Cells against Oxidative Stress through Akt/GSK-3β Pathway

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Current Medical Science 2018年第3期38卷 398-404页

作者： Jin QIN Li-li WANG zhao-yu liu yuan-lin ZOU yu-jie FEI Zheng-xiang liu Department of Cardiology Tongji Hospital Tongji Medical College Huazhong University of Science and Technology Wuhan 430030 China Department of Infection General Hospital of the Yangzte River Shipping Wuhan 430000 China Department of Gastroenterology Tongji Hospital Tongji Medical College Huazhong University of Science and Technology Wuhan 430030 China 2

Ezetimibe was reported to pharmacologically defend against oxidative stress. This study was designed to investigate whether ezetimibe can protect against the oxidative stress induced by oxidized low-density lipoprotein （oxLDL） in vitro and the underlying mechanism. Human umbilical vein endothelial cells （HUVECs） were pretreated with ezetimibe and then exposed to oxLDL for 24 h. TUNEL assay and detection for the protein levels of cleaved caspase-3, Bcl-xl and Bcl-2 were employed to assess the oxLDL-induced endothelial apoptosis. Intracellular reactive oxygen species （ROS） generation was evaluated by measuring dichlorofluorescein （DCF） fluorescence. The activities of endothelial antioxidant enzymes [superoxide dismutase （SOD） and catalase] were tested via an enzymatic assay. The mitochondrial membrane potential （MMP） was monitored by flow cytometry using JC-I staining. Phosphorylation levels of glycogen synthase kinase-3β （p-GSK-3β） and Akt （p-Akt）, as well as total GSK-3β and Akt were determined by Western blotting. The results showed that ezetimibe treatment inhibited HUVECs apoptosis, intracellular ROS production, and enhanced antioxidant enzyme activities elicited by oxLDL. HUVECs exposed to oxLDL alone had reduced mitochondrial function, while ezetimibe pre-intervention could significantly rescue the MMP. Furthermore, the protein levels of p-GSK-3β and p-Akt in ezetimibe-pretreated HUVECs were markedly increased as compared with those in oxLDL-induced HUVECs. However, no significant effect on total GSK- 3β and Akt was found in ezetimibe-pretreated HUVECs. Taken together, it was concluded that ezetimibe protects against oxLDL-induced oxidative stress through restoring the MMP, which may be mediated by Akt-dependent GSK-3β phosphorylation.

关键词： ezetemibe oxidative stress mitochondrial dysfunction Akt/GSK-3β pathway

Event-Triggered Bipartite Consensus Tracking and Vibration Control of Flexible Timoshenko Manipulators Under Time-Varying Actuator Faults

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IEEE/CAA Journal of Automatica Sinica 2024年第5期11卷 1190-1201页

作者： Xiangqian Yao Hao Sun Zhijia zhao yu liu School of Automation Science and Engineering South China University of TechnologyGuangzhou 510640China Yongjiang Laboratory Ningbo 315202 School of Astronautics Harbin Institute of TechnologyHarbin 150001China School of Mechanical and Electrical Engineering Guangzhou UniversityGuangzhou 510006China

For bipartite angle consensus tracking and vibration suppression of multiple Timoshenko manipulator systems with time-varying actuator faults,parameter and modeling uncertainties,and unknown disturbances,a novel distributed boundary event-triggered control strategy is proposed in this *** contrast to the earlier findings,time-varying consensus tracking and actuator defects are taken into account *** addition,the constructed event-triggered control mechanism can achieve a more flexible design because it is not required to satisfy the input-to-state *** achieve the control objectives,some new integral control variables are given by using back-stepping technique and boundary ***,adaptive neural networks are applied to estimate system *** the proposed event-triggered scheme,control inputs can reduce unnecessary ***,tracking errors and vibration states of the closed-looped network can be exponentially convergent into some small fields,and Zeno behaviors can be *** last,some simulation examples are given to state the effectiveness of the control algorithms.

关键词： Vibration satisfy bipartite

A flat-foldable equiangular spiral folding pattern inspired by sunflowers for deployable structures

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Chinese Journal of Aeronautics 2024年第6期37卷 425-438页

作者： Shuangqing yu Jinguo liu Pengyuan zhao Yingying TANG State Key Laboratory of Robotics Shenyang Institute of AutomationChinese Academy of SciencesShenyang 110016China Institutes for Robotics and Intelligent Manufacturing Chinese Academy of SciencesShenyang 110169China University of Chinese Academy of Sciences Beijing 100049China

Flasher origami pattern has been widely utilized to improve the stowage efficiency of deployable ***,flasher origami cannot be folded fully flat,and they still have great potential for optimization in terms of storage volume and folding *** this paper,a flat foldable equiangular spiral folding pattern inspired by the sunflower disk is ***,a parametric design method for this equiangular spiral crease diagram is introduced in ***,a kinematic model of the equiangular spiral folding pattern is established based on the kinematic equivalence between rigid origami and spherical linkages.A simulation of the developed model demonstrates that the equiangular spiral folding pattern can be folded *** the folded ratio as an evaluation index,the calculated results and experiments show that the equiangular spiral crease pattern can yield fewer creases and improve stowage efficiency in comparison to flasher origami *** spiral folding pattern can save a considerable amount of space and provide a new approach to spatially deployable structures.

关键词： Flasher origami Sunflower-inspired Deployable structures Flat-foldability Equiangular spiral folding pattern

Unlocking high-efficiency oxygen evolution reaction through Co-N coordination engineering in Co@N-doped porous carbon core–shell nanoparticles

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Nano Research 2024年第8期17卷 7068-7076页

作者： Shucheng liu yu Shuai Xiaosi Qi zhao Ding Yi liu College of Big Data and Information Engineering Guizhou UniversityGuiyang 550025China College of Physics Guizhou Province Key Laboratory for Photoelectrics Technology and ApplicationGuizhou UniversityGuiyang 550025China

Modulation of metal sites coordination can significantly refine the electronic architecture of catalysts,thereby improving their catalytic *** work successfully developed a core–shell Co@N-doped porous carbon(Co@NC)catalyst by pyrolyzing the COF/MOF(IISERP-COF3/ZIF-67)composite in an inert *** Co@NC catalyst exhibited impressive oxygen evolution reaction(OER)performance,with a small overpotential of 304 mV and a modest Tafel slope of 88.6 mV·dec^(−1) in a 1 M KOH,alongside remarkable stability,maintaining 98.5%of its activity over 13 *** role of IISERP-COF3 was pivotal in preventing Co atom aggregation during the ZIF-67 pyrolysis,which facilitated the creation of mesopores for enhanced mass transport and ***,it effectively modulated the Co-N coordination to fine-tune the electronic structure,thereby optimizing the catalyst's capacity for adsorption of intermediates and boosting its intrinsic *** functional theory(DFT)studies corroborate that the exceptional OER efficiency of Co@NC can be linked to the enhanced Co-N coordination,optimizing the localized electronic structure at the Co active *** study not only proposes an innovative approach for optimizing COF/MOF as effective electrocatalysts but also clears the path for the emergence of affordable,high-performance alternatives to precious metal-based catalysts,marking a significant advancement in sustainable energy technologies.

关键词： covalent organic framework(COF) metal-organic framework(MOF) core-shell structure catalysts oxygen evolution reaction

Oncological outcomes and predictors of radiofrequency ablation of colorectal cancer liver metastases

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World Journal of Gastrointestinal Oncology 2020年第9期12卷 1044-1055页

作者： Chuan-Zhuo Wang Guang-Xin Yan He Xin zhao-yu liu Department of Radiology Shengjing Hospital of China Medical UniversityShenyang 110004Liaoning ProvinceChina

BACKGROUND Surgical resection is considered the standard treatment option for long-term survival in colorectal cancer liver metastasis(CRLM)patients,but only a small number of patients are suitable for resection following *** ablation(RFA)is an accepted alternative therapy for CRLM patients who are not suitable for ***,the relatively high rate of local tumor progression(LTP)is an obstacle to the more widespread use of *** To determine the oncological outcomes and predictors of RFA in CRLM *** A retrospective analyze was performed on the clinical data of 85 consecutive CRLM patients with a combined total of 138 liver metastases,who had received percutaneous RFA treatment at our institution from January 2013 to December ***-enhanced computed tomography was performed the first month after RFA to assess the technique effectiveness of the RFA and to serve as a baseline for subsequent *** Kaplan-Meier method was used to calculate overall survival(OS)and LTP-free survival(LTPFS).The log-rank test and Cox regression model were used for univariate and multivariate analyses to determine the predictors of the oncological *** There were no RFA procedure-related deaths,and the technique effectiveness of the treatment was 89.1%(123/138).The median follow-up time was 30 *** LTP rate was 32.6%(45/138),and the median OS was 36 *** 1-,3-,and 5-year OS rates were 90.6%,45.6%,and 22.9%,*** analysis revealed that tumor size and ablative margin were the factors influencing LTPFS,while extrahepatic disease(EHD),tumor number,and tumor size were the factors influencing *** analysis showed that tumor size larger than 3 cm and ablative margin of 5 mm or smaller were the independent predictors of shorter LTPFS,while tumor number greater than 1,size larger than 3 cm,and presence of EHD were the independent predictors of shorter *** RFA is a safe and effective tr

关键词： Colorectal cancer liver metastasis Radiofrequency ablation Local tumor progression Local tumor progression-free survival Overall survival