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Effect of ytterbium on sodium current and its kinetics in rat hippocampal neurons

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Chinese Science Bulletin 2014年第7期59卷 625-629页

作者： zhengqing du Kun Tian Department of Environmental Economics Shanxi University of Finance and Economics

This study addressed the effects of Yb3+ on voltage-gated sodium currents in rat hippocampal neurons using the whole-cell patch-clamp technique. Voltage-clamp recordings in single neurons were filtered and stored in a computer. Yb3+ increased the amplitude of sodium currents in a concentration-dependent and voltage-dependent manner. The 50 % enhancement concentration of Yb3+ on sodium currents was about 8.97 lmol/L, which was different from the inhibitory effects of Yb3+ on potassium current. The analysis on the activation and inactivation kinetics of Na+ current showed that 100 lmol/L Yb3+ did not change the process of activation and inactivation. In addition, the times reaching the peak of current(t) and inactivated time constant(s) were voltage dependent. 100 lmol/L Yb3+ significantly prolonged the time to peak at-70 and-80 mV. The effect disappeared at the positive direction of-70 mV. Furthermore, Yb3+ decreased s values to more positive values than-80 mV. In total, Yb3+ did not change the process of activation, but impelled inactivated process. Yb3+ mainly increased the Na+ current through changing its conductance. It might be one of the mechanisms that Yb3+ affected the hippocampal neurons.

关键词：海马神经元失活动力学钠电流大鼠全细胞膜片钳技术镱电压依赖性浓度依赖性

The effects of rises in external K^+ on the hyperpolarization-activated cation current I_h in rat dorsal root ganglion neurons

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Science China Chemistry 2009年第8期52卷 1258-1263页

作者： du zhengqing WU WenJie ZHOU YuFen Department of Environmental Science Shanxi University of Finance and EconomicsTaiyuan 030006China

The effects of rises in external K+(Kext) were examined on the hyperpolarization-activated cation current(Ih) in rat dorsal root ganglion neurons using the whole-cell patch clamp *** results showed that Kext increased Ih in a certain concentration and voltage-dependent *** the basal Kext level(4 mmol/L),Ih had a maximal amplitude of 1085 ± 340 pA which was enhanced by ～45% and ～92% at 8 and 16 mmol/L Kext,*** midpoint activation voltage was significantly shifted from -98 mV in the hyperpolarizing direction by 8 and 12 mV at 8 and 16 mmol/L Kext,respectively with alteration of the activation course of *** short time constants of activation became longer with the increasing amplitude of the command potential upon rises in *** long time constants became *** reversal potentials were shifted in the positive direction without significant alterations upon rises in *** to the functional role of Ih,Kext increased Ih,resulting in an enhanced neuronal excitability,which might produce activation potential abnormality and perhaps neuropathic pain involved.

关键词： hyperpolarization-activated inward current external potassium dorsal root ganglion neurons patch clamp

Microscopic defects formation and dynamic mechanical response analysis of Q345 steel plate subjected to explosive load

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Defence Technology（防务技术） 2024年第2期32卷 430-442页

作者： zhengqing Zhou Zechen du Yulong Zhang Guili Yang Ruixiang Wang Yuzhe Liu Peize Zhang Yaxin Zhang Xiao Wang Research Institute of Macro-Safety Science University of Science and TechnologyBeijing100083China School of Civil and Resource Engineering University of Science and TechnologyBeijing100083China China North Industry Advanced Technology Generalization Institute Beijing100089China College of Field Engineering PLA Army Engineering UniversityNanjing210007China School of Mechanical Engineering Nantong UniversityNantong226019China

As the basic protective element, steel plate had attracted world-wide attention because of frequent threats of explosive loads. This paper reports the relationships between microscopic defects of Q345 steel plate under the explosive load and its macroscopic dynamics simulation. Firstly, the defect characteristics of the steel plate were investigated by stereoscopic microscope(SM) and scanning electron microscope(SEM). At the macroscopic level, the defect was the formation of cave which was concentrated in the range of 0-3.0 cm from the explosion center, while at the microscopic level, the cavity and void formation were the typical damage characteristics. It also explains that the difference in defect morphology at different positions was the combining results of high temperature and high pressure. Secondly, the variation rules of mechanical properties of steel plate under explosive load were studied. The Arbitrary Lagrange-Euler(ALE) algorithm and multi-material fluid-structure coupling method were used to simulate the explosion process of steel plate. The accuracy of the method was verified by comparing the deformation of the simulation results with the experimental results, the pressure and stress at different positions on the surface of the steel plate were obtained. The simulation results indicated that the critical pressure causing the plate defects may be approximately 2.01 GPa. On this basis, it was found that the variation rules of surface pressure and microscopic defect area of the Q345 steel plate were strikingly similar, and the corresponding mathematical relationship between them was established. Compared with Monomolecular growth fitting models(MGFM) and Logistic fitting models(LFM), the relationship can be better expressed by cubic polynomial fitting model(CPFM). This paper illustrated that the explosive defect characteristics of metal plate at the microscopic level can be explored by analyzing its macroscopic dynamic mechanical response.

关键词： Explosive load Q345 steel Micro defect Finite element simulation Dynamic response Data fitting

Machine learning aided investigation on the structure-performance correlation of MOF for membrane-based He/H2 separation

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Green Chemical Engineering 2024年第4期5卷 526-532页

作者： Shitong Zhang Yanjing He zhengqing Zhang Chongli Zhong State Key Laboratory of Separation Membranes and Membrane Processes Tiangong University School of Chemical Engineering and Technology Tiangong University School of Textile Science and Engineering Tiangong University

The separation of He/H2using membrane technology has gained significant interest in the field of He extraction from natural gas. One of the greatest challenges associated with this process is the extremely close kinetic diameters of the two gas molecules, resulting in low membrane selectivity. In this study, we investigated the structure-performance relationship of metal-organic framework（MOF） membranes for He/H2separation through molecular simulations and machine learning approaches. By conducting molecular simulations, we identified the potential MOF membranes with high separation performance from the Computation-Ready Experimental（Co RE）MOF database, and the diffusion-dominated mechanism was further elucidated. Moreover, random forest（RF）-based machine learning models were established to identify the crucial factors influencing the He/H2separation performance of MOF membranes. The pore limiting diameter（PLD） and void fraction（φ）, are revealed as the most important physical features for determining the membrane selectivity and He permeability, respectively. Additionally, density functional theory（DFT） calculations were carried out to validate the molecular simulation results and suggested that the electronegative atoms on the pore surfaces can enhance the diffusion-based separation of He/H2, which is critical for improving the membrane selectivities of He/H2. This study offers useful insights for designing and developing novel MOF membranes for the separation of He/H2at the molecular level.

关键词： He/H 2 Membrane separation Molecular simulation Machine learning DFT calculation

镧、钆、镱三种稀土离子诱导背根神经元凋亡及膜上钾电流的比较研究

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中国稀土学报 2011年第4期29卷 496-503页

作者：杜正清杨频山西财经大学环境经济学院山西太原030006 山西大学化学生物学与分子工程教育部重点实验室山西太原030006

运用流式细胞仪和膜片钳技术研究La3+,Gd3+,Yb3+三种稀土离子诱导大鼠背根神经元DRG凋亡以及膜上钾离子通道的影响。结果表明:10,100,1000μmol.L-1LaCl3和GdCl3处理DRG神经元96 h,细胞不出现凋亡;YbCl3处理96 h,细胞的凋亡率明显递增... 详细信息

运用流式细胞仪和膜片钳技术研究La3+,Gd3+,Yb3+三种稀土离子诱导大鼠背根神经元DRG凋亡以及膜上钾离子通道的影响。结果表明:10,100,1000μmol.L-1LaCl3和GdCl3处理DRG神经元96 h,细胞不出现凋亡;YbCl3处理96 h,细胞的凋亡率明显递增。胞外La3+,Gd3+,Yb3+抑制瞬间外向钾电流IA,使IA的激活和失活过程都显著右移,抑制和右移的程度La3+最弱,Gd3+次之,Yb3+最强;胞内的La3+,Gd3+,Yb3+抑制延迟整流钾电流IK,抑制的程度也呈增长趋势。稀土离子在胞内外的结合位点不同;Yb3+较La3+和Gd3+的神经毒性强。

关键词： DRG细胞镧离子钆离子镱离子凋亡钾电流

Development and Application of a Power Law Constitutive Model for Eddy Current Dampers

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Computer Modeling in Engineering & Sciences 2024年第3期138卷 2403-2419页

作者： Longteng Liang Zhouquan Feng Hongyi Zhang zhengqing Chen Changzhao Qian School of Civil Engineering and Architecture Xiamen University of TechnologyXiamen361024China Hunan Provincial Key Laboratory ofWind and Bridge Engineering Hunan UniversityChangsha410082China Fujian Provincial Key Laboratory ofWind Disaster and Engineering Xiamen University of TechnologyXiamen361024China State Key Laboratory of Bridge Engineering Safety and Resilience Hunan UniversityChangsha410082China

Eddy current dampers (ECDs) have emerged as highly desirable solutions for vibration control due to theirexceptional damping performance and durability. However, the existing constitutive models present challenges tothe widespread implementation of ECD technology, and there is limited availability of finite element analysis (FEA)software capable of accurately modeling the behavior of ECDs. This study addresses these issues by developing anewconstitutivemodel that is both easily understandable and user-friendly for FEAsoftware. By utilizing numericalresults obtained from electromagnetic FEA, a novel power law constitutive model is proposed to capture thenonlinear behavior of ECDs. The effectiveness of the power law constitutive model is validated throughmechanicalproperty tests and numerical seismic analysis. Furthermore, a detailed description of the application process ofthe power law constitutive model in ANSYS FEA software is provided. To facilitate the preliminary design ofECDs, an analytical derivation of energy dissipation and parameter optimization for ECDs under harmonicmotionis performed. The results demonstrate that the power law constitutive model serves as a viable alternative forconducting dynamic analysis using FEA and optimizing parameters for ECDs.

关键词： Eddy current damper constitutive model finite element analysis vibration control power law constitutive model

Preparation and Characterization of Biobased Dehydroabietyl Polyethylene Glycol Glycidyl Ether-Grafted Hydroxyethyl Cellulose with High Emulsifying Property

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Journal of Renewable Materials 2024年第1期12卷 103-117页

作者： zhengqing Ding Quan Yang Xinyan Yan Feng Gu Xujuan Huang Zhaosheng Cai School of Chemical and Chemistry Yancheng Institute of TechnologyYancheng224051China

Dehydroabietyl polyethylene glycol glycidyl ether-grafted hydroxyethyl cellulose(HEC)polymer surfactant(DA(EO)5GE-g-HEC)was prepared using ring-opening polymerization with biobased rosin and hydroxyethyl cellulose as *** polyethylene glycol glycidyl ether(DA(EO)5GE)was formed by condensation of dehydroabietyl alcohol polyoxyethylene ether(Rosin derivative:DA(EO)5H)and *** grafting degree of DA(EO)5GE-g-HEC was manipulated by adjusting the mass ratio of HEC and DA(EO)5GE and confirmed by *** to the formula,when m(HEC)/m(DA(EO)2GE)was 1:1~1:5,the grafting rate of DA(EO)5GE in DA(EO)5GE-g-HEC varied from 34.43%to 38.33%.The surface activity and foam properties of DA(EO)5GE-g-HEC aqueous solution were *** results showed that with the increase in grafting rate,the critical micellar concentration(CMC)in aqueous solution changed from 1.28 to 0.96 g/*** results of the thermogravimetric analysis showed that the temperature range of the main stage of mass loss of DA(EO)5GE-g-HEC was 310°C~410°C,and the thermal decomposition processes of the samples with five mass ratios were *** oil in water emulsion was prepared by choosing cyclohexane as the oil phase and DA(EO)5GE-g-HEC as the *** effect of DA(EO)5GE-g-HEC mass fraction on emulsion particle size and stability was *** results suggested that when the oil-water ratio was 8:2 with 0.4%emulsifier,the emulsion droplets were the smallest in terms of particle size and were the most *** rheological test results showed that the apparent viscosity decreased with the increase in shear rate and showed a typical elastic gel phenomenon.

关键词： Rosin hydroxyethyl cellulose surfactant emulsion rheological behaviour

A Practical Regular LDPC Coded Scheme for Physical-Layer Information Security

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China Communications 2024年第5期21卷 190-201页

作者： du Junyi CETC Key Laboratory of Avionic Information System Southwest China Institute of Electronic TechnologyChengdu 610036China

In this paper,we aim to design a practical low complexity low-density parity-check(LDPC)coded scheme to build a secure open channel and protect information from *** this end,we first propose a punctured LDPC coded scheme,where the information bits in a codeword are punctured and only the parity check bits are transmitted to the *** further propose a notion of check node type distribution and derive multi-edge type extrinsic information transfer functions to estimate the security performance,instead of the well-known weak metric bit error *** optimize the check node type distribution in terms of the signal-to-noise ratio(SNR)gap and modify the progressive edge growth algorithm to design finite-length *** results show that our proposed scheme can achieve a lower computational complexity and a smaller security gap,compared to the existing scrambling and puncturing schemes.

关键词： extrinsic information transfer function physical layer scheme secure open channel security gap

Transformer and GAN-Based Super-Resolution Reconstruction Network for Medical Images

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Tsinghua Science and Technology 2024年第1期29卷 197-206页

作者： Weizhi du Shihao Tian Arts&Sciences College Washington University in St.LouisSt.LouisMO 63130USA Department of Electric and Computing Engineering Cornell UniversityIthacaNY 14850USA

Super-resolution reconstruction in medical imaging has become more demanding due to the necessity of obtaining high-quality images with minimal radiation dose,such as in low-field magnetic resonance imaging(MRI).However,image super-resolution reconstruction remains a difficult task because of the complexity and high textual requirements for diagnosis *** this paper,we offer a deep learning based strategy for reconstructing medical images from low resolutions utilizing Transformer and generative adversarial networks(T-GANs).The integrated system can extract more precise texture information and focus more on important locations through global image matching after successfully inserting Transformer into the generative adversarial network for picture ***,we weighted the combination of content loss,adversarial loss,and adversarial feature loss as the final multi-task loss function during the training of our proposed model *** comparison to established measures like peak signal-to-noise ratio(PSNR)and structural similarity index measure(SSIM),our suggested T-GAN achieves optimal performance and recovers more texture features in super-resolution reconstruction of MRI scanned images of the knees and belly.

关键词： super-resolution image reconstruction Transformer generative adversarial network(GAN)