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Essential role of the iron-sulfur cluster binding domain of the primase regulatory subunit Pri2 in DNA replication initiation

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Protein & Cell 2015年第3期6卷 194-210页

作者： lili liu Mingxia Huang Department of Pharmacology and Chemical Biology University of Pittsburgh School of Medicine Pittsburgh PA 15213 USA Department of Biochemistry and Molecular Genetics University of Colorado School of Medicine Aurora CO 80045 USA

DNA primase catalyzes de novo synthesis of a short RNA primer that is further extended by replicative DNA polymerases during initiation of DNA replication. The eukaryotic primase is a heterodimeric enzyme comprising a catalytic subunit Pril and a regulatory subunit Pri2. Pri2 is responsible for facilitating optimal RNA primer synthesis by Pril and mediating interaction between Pril and DNA polymerase o for transition from RNA synthesis to DNA elongation. All eukaryotic Pri2 proteins contain a conserved C-terminal iron-sulfur （Fe-S） cluster-binding domain that is critical for primase catalytic activity in vitro. Here we show that mutations at conserved cysteine ligands for the Pri2 Fe-S cluster markedly decrease the protein stability, thereby causing S phase arrest at the restrictive temperature. Furthermore, Pri2 cysteine mutants are defective in loading of the entire DNA pol α-primase complex onto early replication origins resulting in defective initiation. Importantly, assembly of the Fe-S cluster in Pri2 is impaired not only by mutations at the conserved cysteine ligands but also by increased oxidative stress in the sodlA mutant lacking the Cu/Zn superoxide dismutase. Together these findings highlight the critical role of Pri2＇s Fe-S cluster domain in replication initiation in vivo and suggest a molecular basis for how DNA replication can be influenced by changes in cellular redox state.

关键词： pdmase Pri2 iron-sulfur cluster,replication initiation

Recent advances in modification strategies of silicon-based lithiumion batteries

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Nano Research 2023年第3期16卷 3781-3803页

作者： Wenlei Wang Yu Wang Lixuan Yuan Chaolin You Junwei Wu lili liu Jilei Ye Yunling Wu Lijun Fu State Key Laboratory of Materials-Oriented Chemical Engineering School of Energy Science and EngineeringNanjing Tech UniversityNanjing 211816China

As potential alternatives to graphite,silicon(Si)and silicon oxides(SiO_(x))received a lot of attention as anode materials for lithiumion batteries owing to their relatively low working potentials,high theoretical specific capacities,and abundant resources.However,the commercialization of Si-based anodes is greatly hindered by their massive volume expansion,low conductivity,unstable solid electrolyte interface(SEI),and low initial Coulombic efficiency(ICE).Continuous endeavors have been devoted to overcoming these challenges to achieve practical usage.This review is centered on the major challenges and latest developments in the modification strategies of Si-based anodes,including structure optimization,surface/interface regulation,novel binders,and innovative design of electrolyte.Finally,outlooks and perspectives of Si-based anodes for future development are presented.

关键词： lithium-ion batteries silicon silicon oxides modification strategies

Removal of Cr(Ⅵ)by glutaraldehyde-crosslinked chitosan encapsulating microscale zero-valent iron:Synthesis,mechanism,and longevity

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Journal of Environmental Sciences 2024年第8期142卷 115-128页

作者： Yijun Duan Fang liu Xiang liu Miao Li School of Environment Tsinghua UniversityBeijing 100084China Transportation Institute of Inner Mongolia University Hohhot 010070China

Microscale zero-valent iron(mZVI)has shown great potential for groundwater Cr(Ⅵ)remediation.However,low Cr(Ⅵ)removal capacity caused by passivation restricted the wide use of mZVI.We prepared mZVI/GCS by encapsulating mZVI in a porous glutaraldehydecrosslinked chitosan matrix,and the formation of the passivation layer was alleviated by reducing the contact between zero-valent iron particles.The average pore diameter of mZVI/GCS was 8.775 nm,which confirmed the mesoporous characteristic of this material.Results of batch experiments demonstrated that mZVI/GCS exhibited high Cr(Ⅵ)removal efficiency in a wide range of pH(2-10)and temperature(5-35℃).Common groundwater coexisting ions slightly affected m ZVI/GCS.The material showed great reusability,and the average Cr(Ⅵ)removal efficiency was 90.41%during eight cycles.In this study,we also conducted kinetics and isotherms analysis.Pseudo-second-order model was the most matched kinetics model.The Cr(Ⅵ)adsorption process was fitted by both Langmuir and Freundlich isotherms models,and the maximum Langmuir adsorption capacity of m ZVI/GCS reached243.63 mg/g,which is higher than the adsorption capacities of materials reported in most of the previous studies.Notably,the column capacity for Cr(Ⅵ)removal of a mZVI/GCS-packed column was 6.4 times higher than that of a mZVI-packed column in a 50-day experiment.Therefore,mZVI/GCS with a porous structure effectively relieved passivation problems of mZVI and showed practical application prospects as groundwater Cr(Ⅵ)remediation material with practical application prospects.

关键词： Chitosan Glutaraldehyde mZVI Cr(Ⅵ) Groundwater

The potential mechanism of Isodon suzhouensis against COVID-19 via EGFR/TLR4 pathways

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Food Science and Human Wellness 2024年

作者： Hong Duan Wei Wang Shu Li Han Li Ghulam Jilany Khan Fawang liu Kefeng Zhai lili Li Zhaojun Wei General Clinical Research Center Anhui Wanbei Coal-Electricity Group General Hospital Department of Pharmacology and Therapeutics Faculty of Pharmacy University of Central Punjab College of Biological and Food Engineering Anhui Polytechnic University School of Biological and Food Engineering Engineering Research Center for Development and High Value Utilization of Genuine Medicinal Materials in North Anhui Province Suzhou University School of Food and Biological Engineering Hefei University of Technology

Corona Virus Disease 2019 (COVID-19) has brought the new challenges to scientific research. Isodon suzhouensis has good anti-inflammatory and antioxidant stress effects， which is considered as a potential treatment for COVID-19. The possibility for the treatment of COVID-19 with suzhouensis and its potential mechanism of action were explored by employing molecular docking and network pharmacology. Network pharmacology and molecular docking were used to screen drug targets， and Lipopolysaccharide (LPS) induced RAW264.7 and NR8383 cells inflammation model was used for experimental verification. Collectively a total of 209 possible linkages against 18 chemical components from suzhouensis and 1194 COVID-19 related targets were selected. Among these， 164 common targets were obtained from the intersection of suzhouensis and COVID-19. GO and KEGG enriched 582 function targets and 87 target proteins pathways， respectively. The results from molecular docking studies revealed that rutin， vitexin， isoquercitrin and quercetin had significant binding ability with SARS-CoV-23CLpro and ACE2. In vitro studies showed that Isodon suzhouensis extract (ISE) may inhibit the activation of PI3K/Akt pathway and the expression level of downstream pro-inflammatory factors by inhibiting the activation of EGFR in RAW264.7 cells induced by LPS. In addition， ISE was able to inhibit the activation of TLR4/NF-κB signaling pathway in NR8383 cells exposed to LPS. Overall， the network pharmacology and in vitro studies conclude that active components from suzhouensis have strong therapeutic potential against COVID-19 through multi-target， multi-pathway dimensions and can be a promising candidate against COVID-19.

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Frequency Regulation of VSC-MTDC System with Offshore Wind Farms

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Journal of Modern Power Systems and Clean Energy 2024年第1期12卷 275-286页

作者： Haoyu liu Chongru liu North China Electric Power University Beijing 102206China

Frequency regulation of voltage source converter-based multi-terminal high-voltage direct current(VSC-MTDC)system with offshore wind farms enhances the frequency stability by compensating the power for a disturbed AC system.However,it is difficult to reasonably allocate frequency-regulation resources due to a lack of coordination mechanisms between wind farms and the MTDC system.Moreover,it is difficult for the frequency control of the wind farms to manage changes in wind speed;and the risk of wind-turbine stalls is high.Thus,based on the kinetic energy of wind turbines and the power margin of the converters,the frequency-regulation capability of wind turbines is evaluated,and a dynamic frequency-support scheme considering the real-time frequency-support capability of the wind turbines and system frequency evolution is proposed to improve the frequency-support performance.A power adaptation technique at variable wind speeds is developed;the active power in the frequency-support stage and restoration stage is switched according to the wind speed.A hierarchical zoning frequency-regulation scheme is designed to use the frequency-regulation resources of different links in the MTDC system with wind farms.The simulation results show that the novel frequency-regulation strategy maintains frequency stability with wind-speed changes and avoids multiple frequency dips.

关键词： Wind generation voltage source converter-based multi-terminal high-voltage direct current(VSC-MTDC) frequency regulation cooperative control adaptive control variable wind speed

Characteristics and sources of peroxyacetyl nitrate(PAN)in the rural North China Plain:Results from1-year continuous observations

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Journal of Environmental Sciences 2024年第4期138卷 719-731页

作者： Xin liu Xiaowei He Chenglong Zhang Yifei Song Shuyang Xie Chengtang liu Pengfei liu Yuanyuan Zhang Yujing Mu Junfeng liu Research Center for Eco-Environmental Sciences Chinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China

Peroxyacetyl nitrate(PAN)is an important photochemical pollutant in the troposphere,whereas long-term measurements are scarce in rural areas in North China Plain(NCP),resulting in unclear seasonal variations and sources of PAN in rural NCP.In this study,we conducted a 1-year observation of PAN during 2021-2022 at the rural NCP site.The average concentrations of PAN were 1.10,0.75,0.65,and 0.88 ppbv in spring,summer,autumn,and winter,respectively,with a 1-year average of 0.81±0.60 ppbv.Calculations indicate that the loss of PAN through thermal decomposition in summer accounts for 43.2% of the total formed PAN,which is an important reason for the low concentration of PAN in summer.We speculate that since the correlation between PAN and O_(3) in winter is significantly lower than that in other seasons,the observed regional transport of PAN cannot be ignored in winter.Through budget analysis,regional transport accounted for 12.8% and 55.9% of the observed PAN on the spring and winter pollution days,respectively,which showed that regional transport played key roles during the photochemical pollution of the rural NCP in winter.The potential source contribution function revealed that the transported PAN mainly comes from southern Hebei in spring.In winter,the transported PAN was mainly from Langfang,Hengshui,and southern Beijing.Our findings may aid in understanding PAN variations in different seasons in rural areas and highlight the impact of regional transport on the PAN budget.

关键词： Photochemical pollution Peroxyacetyl nitrate(PAN) Seasonal variations Regional transport Rural area

Constructing a lithiophilic polyaniline coating via in situ polymerization for dendrite-free lithium metal anode

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Nano Research 2023年第6期16卷 8448-8456页

作者： Xiaosong Xiong Qiao Qiao Qi Zhou Xinbing Cheng lili liu Lijun Fu Yuhui Chen Bin Wang Xiongwei Wu Yuping Wu School of Energy and Environment Southeast UniversityNanjing 210096China School of Chemistry and Molecular Engineering Nanjing Tech UniversityNanjing 211816China School of Energy Science and Engineering State Key Laboratory of Materials-Oriented Chemical EngineeringNanjing Tech UniversityNanjing 211816China National Energy Novel Materials Center Institute of Chemical Materials(ICM) China Academy of Engineering Physics(CAEP)Mianyang 621900China Hunan Yinfeng New Energy Co. Ltd.Changsha 430019China

Metallic lithium is regarded as one of the most promising electrode materials to break through the energy density bottleneck of current commercial lithium-ion batteries.However,the practical implementation of lithium metal anode is limited by the unstable electrode interface significantly,which directly induces a low Coulombic efficiency,short cycling lifespan,and dendritic lithium growth behavior.In this study,via in situ electropolymerization,lithiophilic and conformal polyaniline layer is developed to improve the initial lithium nucleation and plating process,reducing the interface charge transfer resistance and promoting uniform lithium plating/stripping behavior.Meanwhile,the polyaniline layer exhibits good adhesion to the substrate.As a result,the Li/Cu half cell delivers a high Coulombic efficiency of 99.1%for 400 cycles at 1.0 mA·cm^(−2)with polyaniline layer.In addition,long-term stable cycling at a current density of 1.0 mA·cm^(−2)for 1300 h has been achieved for lithium metal anode.This strategy provides a new perspective for the practical lithium metal batteries.

关键词： polyaniline in situ electropolymerization electrode interface lithium metal anode

我国文学研究方法论建设历程及其多层次性问题

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文学评论 2024年第3期 24-32页

作者：刘俐俐南开大学文学院

1985年被称为“方法论年”,它原本以更新文艺学美学观念为目的,却开启了我国文学研究方法论建设的第一阶段。这一阶段以方法论的多层次性、方法的内涵与艺术本体对应等基本原理为代表的理论成果,深刻影响了后续建设的走向。第二阶段则... 详细信息

1985年被称为“方法论年”,它原本以更新文艺学美学观念为目的,却开启了我国文学研究方法论建设的第一阶段。这一阶段以方法论的多层次性、方法的内涵与艺术本体对应等基本原理为代表的理论成果,深刻影响了后续建设的走向。第二阶段则为方法论与本体论各自分离性研究。第三阶段集中在方法论的主体意识、解读意识和文学批评方法论等方面的研究。建设历程自然呈现了方法论的多层次属性。多层次性是1985年方法论热时讨论的重要问题之一,已形成了一般方法论、文艺学方法论和文艺内部的具体方法等多层次性的思想成果。其中的一般方法论即马克思主义的理性思维,它给予中间层和最底层方法以灵魂和思维规定。多层次性的另一涵义则为,对应“文学文本多层次结构”属性的方法多层次性及其组合。当下探寻和建设适应文学新样式和结构新方式等变化的批评方法论的任务已经提上了日程。正题一反题一合题是文学研究方法论建设的辩证发展趋势。马克思主义唯物史观及其辩证法作为精髓则贯穿螺旋型发展之始终。

关键词：文学研究方法论方法论原理方法内涵与艺术本体多层次性

High-performance,stable CoNi LDH@Ni foam composite membrane with innovative peroxymonosulfate activation for 2,4-dichlorophenol destruction

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Journal of Environmental Sciences 2024年第7期141卷 235-248页

作者： Yu liu Weibao liu Xinrui Gan Jiangwei Shang Xiuwen Cheng College of Chemistry and Environmental Science Xinjiang Laboratory of Phase Transitions and Microstructures of Condensed Matter PhysicsYili Normal UniversityYining 835000China Key Laboratory for Environmental Pollution Prediction and Control Gansu ProvinceCollege of Earth and Environmental SciencesLanzhou UniversityLanzhou 730000China

In this study,the cobalt-nickel layered double hydroxides(CoNi LDH)were synthesized with a variety of Co/Ni mass ratio,as CoxNiyLDHs.In comparison,Co1Ni3LDH presented the best peroxymonosulfate(PMS)activation efficiency for 2,4-dichlorophenol removal.Meanwhile,CoNi LDH@Nickel foam(CoNi LDH@NF)composite membrane was constructed for enhancing the stability of catalytic performance.Herein,CoNi LDH@NF-PMS system exerted high degradation efficiency of 99.22%within 90 min for 2,4-DCP when[PMS]_(0)=0.4 g/L,Co^(1)Ni^(3)LDH@NF=2 cm×2 cm(0.2 g/L),reaction temperature=298 K.For the surface morphology and structure of the catalyst,it was demonstrated that the CoNi LDH@NF composite membrane possessed abundant cavity structure,good specific surface area and sufficient active sites.Importantly,·OH,SO_(4)·^(-)and^(1)O_(2)played the primary role in the CoNi LDH@NF-PMS system for 2,4-DCP decomposition,which revealed the PMS activation mechanism in CoNi LDH@NF-PMS system.Hence,this study eliminated the stability and adaptability of CoNi LDH@NF composite membrane,proposing a new theoretical basis of PMS heterogeneous catalysts selection.

关键词： CoNi LDH@NF composite membrane Peroxymonosulfate 2,4-dichlorophenol Reactive radicals