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79篇 您的检索式:作者名="Zhikun Li"
    题名 作者 年代 出处 被引量
1Birth of fertile bimaternal offspring following intracytoplasmic injection of parthenogenetic haploid embryonic stem cells显示文摘Zhikun Li Haifeng Wan Guihai Feng Leyun Wang Zhengquan He YukaiWang Xiu-Jie Wang Wei Li Qi Zhou Baoyang Hu 2016Cell Research2016,26,1:15
2Starch grain evidence reveals early pottery function cooking plant foods in North China显示文摘Early pottery sherds excavated in northern China date back to more than 11,000 cal a BP,and are presumed to have been used as cooking vessels.There has been,however,no direct evidence to demonstrate this function.Here we report ancient starch grains recovered from carbonized residues adhering to the bases of flatbottomed vessels excavated from the Zhuannian site dating more than 10,000 cal a BP in the North China Plain.This evidence demonstrates that early pottery was being used to cook cereal grains,particularly millets,and acorns.Because millets were in the process of domestication at thistime,we propose that pottery invention in northern China may have been related to early farming activities.Xiaoyan Yang Zhikun Ma Tao Wang Linda Perry Quan Li Xiujia Huan Jincheng Yu 2014Chinese Science Bulletin2014,59,32:10
3State of the Art and Prospects in Metal-Organic Framework-Derived Microwave Absorption Materials显示文摘Microwave has been widely used in many fields,including communication,medical treatment and military industry;however,the corresponding generated radiations have been novel hazardous sources of pollution threating human’s daily life.Therefore,designing high-performance microwave absorption materials(MAMs)has become an indispensable requirement.Recently,metal-organic frameworks(MOFs)have been considered as one of the most ideal precursor candidates of MAMs because of their tunable structure,high porosity and large specific surface area.Usually,MOF-derived MAMs exhibit excellent electrical conductivity,good magnetism and sufficient defects and interfaces,providing obvious merits in both impedance matching and microwave loss.In this review,the recent research progresses on MOF-derived MAMs were profoundly reviewed,including the categories of MOFs and MOF composites precursors,design principles,preparation methods and the relationship between mechanisms of microwave absorption and microstructures of MAMs.Finally,the current challenges and prospects for future opportunities of MOF-derived MAMs are also discussed.Shuning Ren Haojie Yu Li Wang Zhikun Huang Tengfei Lin Yudi Huang Jian Yang Yichuan Hong Jinyi Liu 2022Nano-Micro Letters2022,14,4:6
4Comparison of four techniques for estimating temporal change of seismic velocity with passive image interferometry显示文摘Passive image interferometry (PII) is becoming a powerful tool for detecting the temporal variations in the Earth's structure,which applies coda wave interferometry to the waveforms from the cross-correlation of seismic ambient noise.There are four techniques for estimating temporal change of seismic velocity with PII:moving-window cross-correlation technique (MWCCT),moving-window cross-spectrum technique (MWCST),stretching technique (ST) and moving-window stretching technique (MWST).In this paper,we use the continuous seismic records from a typical station pair near the Wenchuan MS8.0 earthquake fault zone and generate three sets of waveforms by stacking cross-correlation function of ambient noise with different numbers of days,and then apply four techniques to processing the three sets of waveforms and compare their results.Our results indicate that the techniques based on moving-window (MWCCT,MWCST and MWST) are superior in detecting the change of seismic velocity,and the MWCST can give a better estimate of velocity change than the other moving-window techniques due to measurement error.We also investigate the clock errors and their influences on measuring velocity change.We find that when the clock errors are not very large,they have limited impact on the estimate of the velocity change with the moving-window techniques.Zhikun Liu Jinli Huang Jiaojiao Li 2010Earthquake Science2010,23,5:6
5A review:Modification strategies of nickel-rich layer structure cathode(Ni≥0.8)materials for lithium ion power batteries显示文摘Lithium ion power batteries have undoubtedly become one of the most promising rechargeable batteries at present;nonetheless,they still suffer from the challenges such as requirement of even higher energy density and capacity retention.Nickel-rich layer oxides(Ni≥0.8)become ideal cathode materials to achieve the high specific capacity.Integration of optimization of synthesis process and modification of crystal structure to suppress the capacity fading can obviously improve the performance of the lithium ion batteries.This review presents the recent modification strategies of the nickel-rich layered oxide materials.Unlike in previous reviews and related papers,the specific mechanism about each type of the modification strategies is specially discussed in detail,which is mainly about inhibiting the anisotropic lattice strain and adjusting the cation mixing degree to maintain crystal structure.Based on the recent progress,the prospects and challenges of the modified nickel-rich layer cathodes to upgrade the property of lithium ion batteries are also comprehensively analyzed,and the potential applications in the field of plug-in hybrid vehicles and electric vehicles are further discussed.Haijian Lv Chunli Li Zhikun Zhao Borong Wu Daobin Mu 2021Journal of Energy Chemistry2021,30,9:6
6Plant microremains provide direct evidence for the functions of stone knives from the Lajia site, northwestern China显示文摘A large number of stone knives have been recovered from Neolithic archaeological sites in East Asia.However, direct evidence regarding the functions of the stone knives has been scarce, and hence, their functions have remained controversial. In this study, we recovered and analysed ancient starch grains and phytoliths from residues adhering to stone knives excavated from the Lajia site, Qinghai Province, northwest China, thus providing direct evidence for the functions of the knives. Our analyses were based on the following:(1) an assemblage of 278identifiable starch grains, representing grains from the stems of foxtail millet(Setaria italica) and broomcorn millet(Panicum miliaceum)(65.1 % of the total) and the stems of Hordeum and Triticum species(3.6 % of the total), and(2) an assemblage of 361 identifiable phytoliths,the majority of which were from the stems and leaves of plants such as Panicoideae and related taxa(96 % of the total). Our study demonstrates that one of the functions of the stone knives was the harvesting crops. In addition, a few starch grains from food legumes and roots(3.4 % of the total) indicate that the stone knives were also likely used to process, peel and cut some foods.Zhikun Ma Quan Li Xiujia Huan Xiaoyan Yang Jingyun Zheng Maolin Ye 2014Chinese Science Bulletin2014,59,11:5
7The EGFR-P38 MAPK axis up-regulates PD-L1 through miR-675-5p and down-regulates HLA-ABC via hexokinase-2 in hepatocellular carcinoma cells显示文摘Background:Immunotherapy has been shown to be a promising strategy against human cancers.A better understanding of the immune regulation in hepatocellular carcinoma(HCC)could help the development of immunotherapy against HCC.The epidermal growth factor receptor(EGFR)signaling is frequently activated in HCC and plays important roles in tumorigenesis.However,its role in HCC immunity is still largely unknown.This study aimed to investigate the impact of EGFR signaling on programmed death-ligand 1(PD-L1)and human leukocyte antigen class-I(HLA-I)expression in HCC cells and its underlying mechanisms.Methods:The expression of phosphorylated EGFR(p-EGFR),PD-L1,and HLAI(HLA-ABC)in HCC specimens was detected by immunohistochemistry,and their correlations were analyzed.PD-L1 and HLA-ABC expression in EGFRactivated HCC cells were detected by quantitative real-time PCR,Western blotting,and flow cytometry,and T cell-mediated lysis was performed to test the immunosuppressive effects of PD-L1 and HLA-ABC alterations in HCC cells.Furthermore,the underlying mechanisms of EGFR activation-induced PD-L1 up-regulation and HLA-ABC down-regulation were explored by animal experiments,luciferase reporter assay,and gene gain-and loss-of-function studies.Results:p-EGFR was positively correlated with PD-L1 and negatively correlated with HLA-ABC expression in HCCs.EGFR activation by its ligand EGF up-regulated PD-L1 and down-regulated HLA-ABC in HCC cells,which was functionally important and could be abolished by the EGFR inhibitor,gefitinib,both in vitro and in vivo.Mechanistically,enhanced P38 mitogenactivated protein kinase(MAPK)activation down-regulated microRNA-675-5p(miR-675-5p)and up-regulated glycolysis-related enzyme hexokinase 2(HK2);miR-675-5p down-regulation enhanced the stability of PD-L1 mRNA probably via the 3’-untranslated region(3’-UTR)of PD-L1 and thereby caused PD-L1 accumulation,and HK2 up-regulation enhanced aerobic glycolysis and mediated a decrease in HLA-ABC.Conclusions:The EGFR-P38 MAPK axis could up-regulate PD-L1 through miR-675-5p and down-regulate HLA-ABC via HK2 in HCC cells.Our study reveals a novel signaling network that may cause immune suppression in HCC and suggests that EGFR signaling can be targeted for HCC immunotherapy.Zongcai Liu Fen Ning Yanna Cai Huiying Sheng Ruidan Zheng Xi Yin Zhikun Lu Ling Su Xiaodan Chen Chunhua Zeng Haifang Wang Li Liu 2021Cancer Communications2021,41,1:5
8Cu(I)-Catalyzed Three-Component Coupling of Trifluoromethyl Ketone N-Tosylhydrazones, Alkynes and Azides: Synthesis of Difluoromethylene Substituted 1,2,3-Triazoles显示文摘一 trifluoromethyl 酉同类 N-tosylhydrazones,炔属羟和叠氮化物的催化 CuI 的三部件的联合被开发了。reactionrepresents 存取 difluoromethylene 的一个直接方法代替了 1,2,3-triazoles。机械学地,反应跟随包含 Cu (I) triazolide 中介, Cu (I) carbene 形成,迁移的插入,和氟化物消除的形成的一条小径,这被建议了。Thetransformation 被温和条件,宽底层范围和高效率展示。Zhikun Zhang Qi Zhou Weizhi Yu Tianjiao Li Yan Zhang Jianbo Wang 2017Chinese Journal of Chemistry2017,35,4:4
9Synergistic engineering of CRISPR-Cas nucleases enables robust mammalian genome editing显示文摘The naturally occurring prokaryotic CRISPR-Cas systems provide valuable resources for the development of new genome-editing tools.However,the majority of prokaryotic Cas nucleases exhibit poor editing efficiency in mammalian cells,which significantly limits their utility.Here,we have developed a method termed Improving Editing Activity by Synergistic Engineering(MIDAS).This method exerts a synergistic effect to improve mammalian genome-editing efficiency of a wide range of CRISPR-Cas systems by enhancing the interactions of Cas nuclease with the protospacer adjacent motif(PAM)and the single-stranded DNA(ssDNA)substrate in the catalytic pocket simultaneously.MIDAS robustly and significantly increased the gene-editing efficiency of Cas12i,Cas12b,and CasX in human cells.Notably,a Cas12i variant,Cas12iMax,exhibited robust activity with a very broad PAM range(NTNN,NNTN,NAAN,and NCAN)and higher efficiency than the current widely used Cas nucleases.A high-fidelity version of Cas12iMax(Cas12iHiFi)has been further engineered to minimize off-target effects.Our work provides an expandable and efficacious method for engineering Cas nucleases for robust mammalian genome editing.Yangcan Chen Yanping Hu Xinge Wang Shengqiu Luo Ning Yang Yi Chen Zhikun Li Qi Zhou Wei Li 2022The Innovation2022,3,4:3
10Continuous and comprehensive atmospheric observations in Beijing:a station to understand the complex urban atmospheric environment显示文摘Due to profound impact on climate and human health,air quality has attracted attention from all levels of the civil society.The key step in the provision of required tools for the society to tackle the complex air quality problem is to characterize it in a comprehensive manner with a long-term perspective.Here,we describe a continuous and comprehensive observation station and its accompanying state-ofthe-art instrumentation that was established to investigate the complex urban atmospheric environment in a rapidly developing Chinese Megacity.The station,located in downtown Beijing,aims to study air quality by identifying the major atmospheric pollutants and key processes determining their formation and loss mechanisms.A few hundreds of parameters are continuously measured with the state-of-the-art instruments,including trace gas concentrations,aerosol particle size distributions,and mass concentrations,covering aerosol particle chemical composition from molecules to micrometer-sized aerosol particles.This produced long-term,comprehensive big data with around 1�10^(11)bytes per year.In this paper,we provide an overview on the facilities of the station,the instrumentation used,the workflow of continuous observations and examples of results from 2018 to 2019 and a basis for establishing a modern long-term,comprehensive atmospheric urban observation station in other megacities.Yongchun Liu Chao Yan Zemin Feng Feixue Zheng Xiaolong Fan Yusheng Zhang Chang Li Ying Zhou Zhuohui Lin Yishou Guo Ying Zhang Li Ma Wenshuo Zhou Zhikun Liu Lubna Dada Kaspar Dallenbach Jenni Kontkanen Runlong Cai Tommy Chan Biwu Chu Wei Du Lei Yao Yonghong Wang Jing Cai Juha Kangasluoma Tom Kokkonen Joni Kujansuu Anton Rusanen Chenjuan Deng Yueyun Fu Rujing Yin Xiaoxiao Li Yiqun Lu Yiliang Liu Chaofan Lian Dongsen Yang Weigang Wang Maofa Ge Yuesi Wang Douglas R.Worsnop Heikki Junninen Hong He Veli-Matti Kerminen Jun Zheng Lin Wang Jingkun Jiang Tuukka Petaja Federico Bianchi Markku Kulmala 2020Big Earth Data2020,4,3:3
11A new fragment re-allocation strategy for NoSQL database systems显示文摘Zhikun CHEN Shuqiang YANG Shuang TAN Li HE Hong YIN Ge ZHANG 2015Frontiers of Computer Science2015,9,1:3
12A bestrophin-like protein modulates the proton motive force across the thylakoid membrane in Arabidopsis显示文摘During photosynthesis, photosynthetic electron transport generates a proton motive force(pmf) across the thylakoid membrane, which is used for ATP biosynthesis via ATP synthase in the chloroplast. The pmf is composed of an electric potential(△Ψ) and an osmotic component(△pH).Partitioning between these components in chloroplasts is strictly regulated in response to fluctuating environments.However, our knowledge of the molecular mechanisms that regulate pmf partitioning is limited. Here, we report a bestrophin-like protein(At Best), which is critical for pmf partitioning. While the Dp H component was slightly reduced in atbest, the △Ψ component was much greater in this mutant than in the wild type, resulting in less efficient activation of nonphotochemical quenching(NPQ) upon both illumination and a shift from low light to high light. Although no visible phenotype was observed in the atbest mutant in the greenhouse, this mutant exhibited stronger photoinhibition than the wild type when grown in the field. At Best belongs to the bestrophin family proteins, which are believed to function as chloride(Cl^-) channels. Thus, our findings reveal an Researimportant Cl^- channel required for ion transport and homeostasis across the thylakoid membrane in higher plants. These processes are essential for fine-tuning photosynthesis under fluctuating environmental conditions.Zhikun Duan Fanna Kong Lin Zhang Wenjing Li Jiao Zhang Lianwei Peng 2016Journal of Integrative Plant Biology2016,58,10:2
13Surfactants Mediated Synthesis of Highly Crystalline Thin Films of Imine-Linked Covalent Organic Frameworks on Water Surface显示文摘Imine-linked covalent organic frameworks(COFs)have attracted extensive attention due to designable structures,tunable properties,and excellent thermal and chemical stability.They were typically obtained as insoluble and unprocessable powders,which seriously limits their full promise.Progress has been made in the synthesis of thin films of imine-linked COFs by interfacial synthesis.However,the synthesis of highly crystalline,self-supporting thin films of COFs remains challenging.Here,we employed a surfactants-mediated method to synthesize such films at an air-water interface,showed the films could be transferred onto arbitrary substrates on demand,and demonstrated the generality of the methodology with two different COFs.We found that the length of hydrophobic segments of surfactants played a key role in determination of the crystallinity and single crystalline domain size of the films.This work provides a feasible strategy to generate highly crystalline thin films of COFs.Zhaowei Ou Zihao Liang Xin Dong Fanglin Tan Li Gong Pei Zhao Honglei Wang Wei Liu Zhikun Zheng 2021Chinese Journal of Chemistry2021,39,12:2
14Occurrence, variations, and risk assessment of neonicotinoid insecticides in Harbin section of the Songhua River, northeast China显示文摘Neonicotinoid insecticides(NNIs)have been intensively used and exploited,resulting in their presence and accumulation in multiple environmental media.We herein investigated the current levels of eight major NNIs in the Harbin section of the Songhua River in northeast China,providing the first systematic report on NNIs in this region.At least four NNIs in water and three in sediment were detected,with total concentrations ranging from 30.8 to 135 ng L^(-1) and from 0.61 to 14.7 ng g^(-1) dw,respectively.Larger spatial variations in surface water NNIs concentrations were observed in tributary than mainstream(p<0.05)due to the intensive human activities(e.g.,horticulture,urban landscaping,and household pet flea control)and the discharge of wastewater from many treatment plants.There was a significant positive correlation(p<0.05)between the concentrations of residual imidacloprid(IMI),clothianidin(CLO),and S4NNIs in the sediment and total organic carbon(TOC).Due to its high solubility and low octanol-water partition coefficient(Kow),the sediment-water exchange behavior shows that NNIs in sediments can re-enter into the water body.Human exposure risk was assessed using the relative potency factor(RPF),which showed that infants have the highest exposure risk(estimated daily intake(SIMIeq EDI):31.9 ng kg^(-1) bw$d^(-1)).The concentration thresholds of NNIs for aquatic organisms in the Harbin section of the Songhua River were determined using the species sensitivity distribution(SSD)approach,resulting in a value of 355 ng L^(-1) for acute hazardous concentration for 5%of species(HC5)and 165 ng L^(-1) for chronic HC5.Aquatic organisms at low trophic levels were more vulnerable to potential harm from NNIs.Zhikun Liu Song Cui Leiming Zhang Zulin Zhang Rupert Hough Qiang Fu Yi-Fan Li Lihui An Mingzhi Huang Kunyang Li Yuxin Ke Fuxiang Zhang 2021Environmental Science and Ecotechnology2021,,4:2
15Fabrication of all-transparent polymer-based and encapsulated nanofluidic devices using nano-indentation lithography显示文摘In this paper,we describe a novel and simple process for the fabrication of all-transparent and encapsulated polymeric nanofluidic devices using nano-indentation lithography.First,a nanomechanical probe is used to‘scratch’nanoscale channels on polymethylmethacrylate(PMMA)substrates with sufficiently high hardness.Next,polydimethylsiloxane(PDMS)is used twice to duplicate the nanochannels onto PDMS substrates from the‘nano-scratched’PMMA substrates.A number of experiments are conducted to explore the relationships between the nano-indentation parameters and the nanochannel dimensions and to control the aspect ratio of the fabricated nanochannels.In addition,traditional photolithography combined with soft lithography is employed to fabricate microchannels on another PDMS‘cap’substrate.After manually aligning the substrates,all uncovered channels on two separate PDMS substrates are bonded to achieve a sealed and transparent nanofluidic device,which makes the dimensional transition from microscale to nanoscale feasible.The smallest dimensions of the achievable nanochannels that we have demonstrated thus far are of~20 nm depth and~800 nm width,with lengths extendable beyond 100μm.Fluid flow experiments are performed to verify the reliability of the device.Two types of colloidal solution are used to visualize the fluid flow through the nanochannels,that is,ethanol is mixed with gold colloid or fluorescent dye(fluorescein isothiocyanate),and the flow rate and filling time of liquid in the nanochannels are estimated based on time-lapsed image data.The simplicity of the fabrication process,bio-compatibility of the polymer substrates,and optical transparency of the nanochannels for flow visualization are key characteristics of this approach that will be very useful for nanofluidic and biomolecular research applications in the future.Cong Wu Tiffany G.Lin Zhikun Zhan Yi Li Steve C.H.Tung William C.Tang Wen J.Li 2017Microsystems & Nanoengineering2017,3,1:2
16A New Family of Galeaspids(Jawless Stem-Gnathostomata) from the Early Silurian of Chongqing, Southwestern China显示文摘A new genus and species of agnathan Eugaleaspidiformes(Galeaspida), Yongdongaspis littoralis gen. et sp. nov., is described from the Llandovery(lower Silurian) Huixingshao Formation at Yongdong Town, Xiushan County, Chongqing, southwestern China. This new Telychian taxon morphologically exhibits some transitional states between Sinogaleaspidae and a cluster of higher eugaleaspidiforms containing Tridensaspidae, Eugaleaspidae, Yunnanogaleaspis, and Nochelaspis, which we term here as the ’eugaleaspid cluster’. Phylogenetic analysis of an extended character matrix of Galeaspida reveals Yongdongaspis, on which Yongdongaspidae fam. nov. is erected, as the sister taxon of this ’eugaleaspid cluster’, supported by two synapomorphies, the presence of one median transverse canal, and two lateral transverse canals leaving from the infraorbital canal. As the first fish described from the Llandovery Huixingshao Formation in Chongqing, Yongdongaspis provides new fossil evidence for the subdivision and correlation of the Upper Red Beds in South China.CHEN Yang GAI Zhikun LI Qiang WANG Jianhua PENG Lijian WEI Guangbiao ZHU Min 2022Acta Geologica Sinica(English Edition)2022,96,2:2
17A Preliminary Study on a Seismotectonic Model for the Active Faults in the Xining Urban Area显示文摘On the basis of the Xining active urban fault survey,we studied the relationship between the active urban fault and fold deformation.The result of this research shows that the Huangshuihe fault and the NW-striking fault on the northern bank of the Huangshuihe River are tensional faults on top of an anticline,the Nanchuanhe fault is a transverse tear fault resulting from differential folding on two sides of the fault,the east bank of the Beichuanhe River fault is a compressional fault developed on the core or climb of a syncline.By balance profile analysis of fold deformation and inversion of gravity anomaly data,we obtained the depth of the detachment plane and established the seismotectonic model of the Xining urban area.Based on the seismotectonic model,we analyzed the earthquake potential of the active urban fault.Tian Qinjian Li Zhimin Zhang Junlong Ren Zhikun 2008Earthquake Research in China2008,22,1:2
18Energy-efficient CoMP precoding in heterogeneous networks显示文摘Xu Zhikun Yang Chenyang Li Ye G 2014Signal Processing IEEE Transactions on2014,62,4:1
19Gata4, Tbx5 and Baf60c induce differentiation of adipose tissue-de- rived mesenchymal stem cells into beating cardiomyocytes 显示文摘LI Qiong GUO Zhikun CHANG Yuqiao 2015Int J Biochem Cell Biol2015,66,:1
20Energy-Efficient Wireless Communications : Tutorial, Survey, and Open Issues 显示文摘LI GEOFFREY YE XU Zhikun XIONG Cong 2011IEEE Wireless Communications2011,18,6:1
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