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Optimization on crystallization process of the magnetic core lysozyme

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Particuology 2024年第4期87卷 106-113页

作者： Lixia hou Chunxiao Qu Min Su Zhihan Liang qi Hao School of Chemical Engineering Hebei University of TechnologyTianjin300130China

The continuous growth of the biomedical market highlights the significance of improvement in the ef-ficiency of batch production for protein drug crystals.Herein,we investigated the effect of polymer-modified Fe_(3)O_(4) nanoparticles on lysozyme(Lys)crystallization at different conditions,using function-alized Fe_(3)O_(4) magnetic nanoparticles(Polymer C@Fe_(3)O_(4))as nucleation agents.The study revealed that the surface charge density of Polymer C@Fe_(3)O_(4) was highest at a modification mass ratio of Fe_(3)O_(4) to Polymer C is 8∶3.This ratio facilitates the augmentation of electrostatic interaction and the promotion of crys-tallization.By adding 15%of the PolymerC@Fe_(3)O_(4) prepared from Fe_(3)O_(4) with an average particle size of 150 nm,the magnetic core lysozyme(M-Lys)crystals with an average particle size of 11.08μm,narrow size distribution,and regular morphology were obtained in a yield of 82.42%within 60 min.

关键词： Protein Crystallization Magnetic particle Lysozyme

Effect of short neuropeptide F signaling on larval feeding in Mythimna separata

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Insect Science 2024年第2期31卷 417-434页

作者： mei-mei Li qi Yang Li-Hui Chen Yan-Ying Li Jun-Xiang Wu Xiang-Li Xu State Key Laboratory of Crop Stress Biology in Arid Areas College of Plant ProtectionNorthwest A&F UniversityYanglingShaanxi ProvinceChinaand School of Agricultural Sciences Jiangxi Agricultural UniversityNanchangChina

Mythimna separata is a notorious phytophagous pest which poses serious threats to cereal crops owing to the gluttony of the larvae.Because short neuropeptide F(sNPF)and its receptor sNPFR are involved in a diversity of physiological functions,especially in functions related to feeding in insects,it is a molecular target for pest control.Herein,an sNPF and 2 sNPFRs were identified and cloned from M.separata.Bioinformatics analysis revealed that the sNPF and its receptors had a highly conserved RLRFamide C-terminus and 7 transmembrane domains,respectively.The sNPF and its receptor genes were distributed across larval periods and tissues,but 2 receptors had distinct expression patterns.The starvation-induced assay elucidated that sNPF and sNPFR expression levels were downregulated under food deprivation and recovered with subsequent re-feeding.RNA interference knockdown of sNPF,sNPFR1,and sNPFR2 by injection of double-stranded RNA into larvae not only suppressed food consumption and increased body size and weight,but also led to decrease of glycogen and total lipid contents,and increase of trehalose compared with double-stranded green fluorescent protein injection.Furthermore,molecular docking was performed on the interaction mode between sNPFR protein and its ligand sNPF based on the 3-dimensional models constructed by AlphaFold;the results indicated that both receptors were presumably activated by the mature peptide sNPF-2.These results revealed that sNPF signaling played a considerably vital role in the feeding regulation of M.separata and represents a potential control target for this pest.

关键词： feeding regulation Mythimna separata pest control target RNA interference short neuropeptide F sNPF receptors

A novel Ce_(0.485)Zr_(0.485)Y_(0.03)O_(2) composite oxide with surface doping of Y and its application in Pd-only three-way catalyst

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Rare Metals 2024年第2期43卷 749-757页

作者： Zheng Zhao Wei-Xin Zhao Yong-qi Zhang mei-Sheng Cui Yong-Ke hou Dong-Ming Chen Juan-Yu Yang Zong-Yu Feng Xiao-Wei Huang National Engineering Research Center for Rare Earth Grirem Advanced Materials Co.Ltd.GRINM Group Corporation LimitedBeijing100088China Griem Hi-Tech Co.Ltd. Langfang065000China Rare Earth Functional Materials(Xiong’an)Innovation Venter Co.Ltd. Baoding071700China

The ceria-zirconia compound oxide-supported noble metal Pd(Pd@CZ)is widely used in three-way catalyst.Moreover,the surface structure of CZ plays an important role in catalytic activity of Pd.However,how to regulate the surface structure of CZ and clarify the structure–activity relationship is still a challenge.In this paper,a strategy is proposed to develop high activity Pd@CZ nanocatalysts by tuning Y doping sites in CZ.The precipitate-deposition method is developed to prepare the novel Ce_(0.485)Zr_(0.485)Y_(0.03)O_(2) composite with surface doping of Y(CZ-Y-S).In addition,the Pd@CZ-Y-S(Pd supported on CZ-Y-S)exhibits superior catalytic activity for HC,CO,and NO oxide,wherein,for CO and C_(3)H_(6) oxidation,the low-temperature activity of Pd@CZ-Y-S is still 20%higher than that of Pd@CZ-Y-B(Y bulk doping)and commercial Pd@CZ after 1000℃/4 h aging.The effect mechanism is further studied by density functional theory(DFT)calculation.Compared with Pd@CZ-Y-B,Pd@CZ-Y-S shows the lower CO oxide reaction energy barriers due to the weaker adsorption strength of O2.The Y surface doping strategy could provide valuable insights for the development of highly efficient Pd@CZ catalyst with extensive applications.

关键词： Rare earth Ceria-zirconia-supported Pd Surface doping Experiment and theory Catalytic application

Investigation on the Deformation and Failure Patterns of Loess Cut Slope Based on the Unsaturated Triaxial Test in Yan'an,China

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Journal of Earth Science 2024年第1期35卷 235-247页

作者： Lina Ma Shengwen qi Songfeng Guo qiangbing Huang Xiaokun hou Key Laboratory of Shale Gas and Geoengineering Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China University of Chinese Academy of Sciences Beijing 100049China Innovation Academy for Earth Science Chinese Academy of SciencesBeijing 100029China Department of Geological Engineering Chang'an UniversityXi'an 710054China

The large-scale implementation of the Gully Stabilization and Land Reclamation(GSLR)project induces various failures of loess slopes due to excavation in Yan'an,China.However,the deformation and failure behavior of these excavated loess slopes have not been fully understood.In this study,field investigation was undertaken for analyzing the distributions and failure features of excavation-induced loess slope failures.It is found that plastic failure mainly occurs in Q_(3) loess layers and brittle failure in Q_(2).To understand the underlying failure mechanism,a series of triaxial shear tests were conducted on intact Q_(3) and Q_(2) loess samples that with different water contents,namely natural water content(natural),dry side of the natural value(drying 5%),and wet side(wetting 5%).The characteristics of stress-strain curves and failure modes of the samples were analyzed.Results show that the stress-strain curves of Q_(2) samples are dominated by strain-softening characteristics,while Q_(3) samples mainly exhibit strain-harden features except in the drying state.Correspondingly,shear failures of Q_(3) specimens are mainly caused by shear crack planes(single,X or V-shaped).For Q_(2) loess,the dominance of tensile cracks is observed on the surface of damaged specimens.These disclose the different failure modes of excavated slopes located in different strata,that is,the arc sliding failure of Q_(3) loess slopes and the stepped tensile failure of Q_(2) loess slopes,and are helpful in the design and management of the ongoing GSLR projects in the Loess Plateau.

关键词： loess slope slope stability failure patterns deformation

Phase-field lattice-Boltzmann study on fully coupled thermal-solute-convection dendrite growth of Al-Cu alloy

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China Foundry 2024年第2期21卷 125-136页

作者： Yin-qi qiu Meng-wu Wu Xun-peng qin Shou-mei Xiong Hubei Key Laboratory of Advanced Technology for Automotive Components Wuhan University of TechnologyWuhan 430070China Hubei Longzhong Laboratory Xiangyang 441000HubeiChina School of Materials Science and Engineering Tsinghua UniversityBeijing 100084China

Dendrite growth is a complex liquid-solid phase transition process involving multiple physical factors.A phase-field lattice-Boltzmann method was developed to simulate the two-and three-dimension dendrite growth of Al-Cu alloy.The effect of fully coupled thermal-solute-convection interaction on the dendrite growth was investigated by incorporating a parallel-adaptive mesh refinement algorithm into the numerical model.By accurately reproducing the latent heat release,solute diffusion and convective transport behaviors at the liquidsolid interface,the interaction mechanism among thermal-solute-convection transport as well as their coupling effects on the dendrite growth dynamics were discussed.The simulation results show that the release of latent heat slows down the dendrite growth rate,and both natural and forced convection disrupt the symmetrical growth of dendrites.Their combination makes the growth of dendrites more complex,capturing important physical aspects such as recalescence,dendrite tip splitting,dendrite tilting,dendrite remelting,and solute plume in the simulation case.Based on the robustness and powerful ability of the numerical model,the formation mechanisms of these physical aspects were revealed.

关键词： simulation phase field dendrite growth thermal-solute-convection interaction

Local State Capacity and Uneven Taxation across Industrial Firms

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China & World Economy 2024年第3期32卷 191-214页

作者： Linke hou Zhikuo Liu qi Zhang Xiaolu Zhao the Economic Research Center Shandong UniversityChina China Center for Economic Studies Fudan UniversityChina School of Economics Ocean University of ChinaChina

In this research we investigate the association between local state capacity(LSC)and effective tax burdens(ETBs)on industrial firms within counties between 1998 and 2013.The LSC measures a state's capacity for policy implementation and specifically its ability to acquire low-cost agricultural land for nonagricultural(industrial or commercial)purposes.Based on China's government-led development experience since the 1990s,we draw on two unique household survey datasets to capture LSC at county level.We find robust evidence that greater LSC was associated with much lower ETBs on large industrial firms.This taxation pattern implies local government's primary reliance on larger manufacturing firms,while the ETBs for small-and-medium enterprises are not as prominently addressed.This research highlights that LSC can affect both the amount of revenue a local government can generate and the methods it uses to collect these revenues.

关键词： China effective tax burdens land requisition local government local state capacity

Improved forecasting via physics-guided machine learning as exemplified using“21·7”extreme rainfall event in Henan

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Science China Earth Sciences 2024年第5期67卷 1652-1674页

作者： qi ZHONG Zhicha ZHANG Xiuping YAO Shaoyu hou Shenming FU Yong CAO Linguo JING China Meteorological Administration Training Center Beijing 100081China State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesBeijing 100081China Zhejiang Meteorological Observatory Hangzhou 310017China Hebei Provincial Weather Modification Center Shijiazhuang 050020China Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029China National Meteorological Center Beijing 100081China School of Computer Science Chengdu University of Information TechnologyChengdu 610225China

As a natural disaster,extreme precipitation is among the most destructive and influential,but predicting its occurrence and evolution accurately is very challenging because of its rarity and uniqueness.Taking the example of the“21·7”extreme precipitation event(17–21 July 2021)in Henan Province,this study explores the potential of using physics-guided machine learning to improve the accuracy of forecasting the intensity and location of extreme precipitation.Three physics-guided ways of embedding physical features,fusing physical model forecasts and revised loss function are used,i.e.,(1)analyzing the anomalous circulation and thermodynamical factors,(2)analyzing the multi-model forecast bias and the associated underlying reasons for it,and(3)using professional forecasting knowledge to design the loss function,and the corresponding results are used as input for machine learning to improve the forecasting accuracy.The results indicate that by learning the relationship between anomalous physical features and heavy precipitation,the forecasting of precipitation intensity is improved significantly,but the location is rarely adjusted and more false alarms appear.Possible reasons for this are as follows.The anomalous features used here mainly contain information about large-scale systems and factors which are consistent with the model precipitation deviation;moreover,the samples of extreme precipitation are sparse and so the algorithm used here is simple.However,by combining“good and different”multi models with machine learning,the advantages of each model are extracted and then the location of the precipitation center in the forecast is improved significantly.Therefore,by combining the appropriate anomalous features with multi-model fusion,an integrated improvement of the forecast of the rainfall intensity and location is achieved.Overall,this study is a novel exploration to improve the refined forecasting of heavy precipitation with extreme intensity and high variability,and provides a reference for the deep fusion of

关键词： Extreme precipitation event Refined assessment Anomalous physical features Multi-model fusion Machine learning

Effects of Hydrogen Charging Time and Pressure on the Hydrogen Embrittlement Susceptibility of X52 Pipeline Steel Material

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Acta Metallurgica Sinica(English Letters) 2024年第2期37卷 293-307页

作者： Hong-Jiang Wan Xiao-qi Wu Hong-Liang Ming Jian-qiu Wang En-hou Han School of Materials Science and Engineering University of Science and Technology of ChinaShenyang110016China CAS Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang110016China School of Materials Science and Engineering Northeastern UniversityShenyang110819China Institute of Corrosion Science and Technology Guangzhou510530China

The effects of hydrogen charging time and pressure on the hydrogen embrittlement(HE)susceptibility of X52 pipeline steel material are studied by slow strain rate tensile tests.The fracture morphologies of the specimens are observed by scanning electron microscopy.The HE susceptibility of the X52 pipeline steel material increases with an increase in both hydrogen charging time and hydrogen pressure.At a charging time of 96 h,the HE susceptibility index reaches 45.86%,approximately 3.6 times that at a charging time of 0 h.Similarly,a charging pressure of 4 MPa results in a HE susceptibility index of 31.61%,approximately 2.5 times higher than that at a charging pressure of 0.3 MPa.

关键词： Hydrogen embrittlement X52 pipeline steel material Tubular specimen Hydrogen charging time Hydrogen charging pressure

The action mechanism by which C1q/tumor necrosis factor-related protein-6 alleviates cerebral ischemia/reperfusion injury in diabetic mice

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Neural Regeneration Research 2024年第9期19卷 2019-2026页

作者： Bo Zhao mei Li Bingyu Li Yanan Li qianni Shen Jiabao hou Yang Wu Lijuan Gu Wenwei Gao Department of Anesthesiology Renmin Hospital of Wuhan UniversityWuhanHubei ProvinceChina Central Laboratory Renmin Hospital of Wuhan UniversityWuhanHubei ProvinceChina Department of Critical Care Medicine Renmin Hospital of Wuhan UniversityWuhanHubei ProvinceChina

Studies have shown that C1q/tumor necrosis factor-related protein-6 (CTRP6) can alleviate renal ischemia/reperfusion injury in mice. However, its role in the brain remains poorly understood. To investigate the role of CTRP6 in cerebral ischemia/reperfusion injury associated with diabetes mellitus, a diabetes mellitus mouse model of cerebral ischemia/reperfusion injury was established by occlusion of the middle cerebral artery. To overexpress CTRP6 in the brain, an adeno-associated virus carrying CTRP6 was injected into the lateral ventricle. The result was that oxygen injury and inflammation in brain tissue were clearly attenuated, and the number of neurons was greatly reduced. In vitro experiments showed that CTRP6 knockout exacerbated oxidative damage, inflammatory reaction, and apoptosis in cerebral cortical neurons in high glucose hypoxia-simulated diabetic cerebral ischemia/reperfusion injury. CTRP6 overexpression enhanced the sirtuin-1 signaling pathway in diabetic brains after ischemia/reperfusion injury. To investigate the mechanism underlying these effects, we examined mice with depletion of brain tissue-specific sirtuin-1. CTRP6-like protection was achieved by activating the sirtuin-1 signaling pathway. Taken together, these results indicate that CTRP6 likely attenuates cerebral ischemia/reperfusion injury through activation of the sirtuin-1 signaling pathway.

关键词： brain C1q/tumor necrosis factor-related protein-6 cerebral apoptosis diabetes inflammation ischemia/reperfusion injury neuron neuroprotection oxidative damage Sirt1