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On the electric behaviour of conductive grease inside the contact zone

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Friction 2024年第4期12卷 683-697页

作者： Yuxin ZHOU jinjie LIU Xinming LI He CHONG Bo HAN Qinghua BAI SKF(Shanghai)Automotive Technologies Co. Ltd.Shanghai 201814China School of Mechanical and Automotive Engineering Qingdao University of TechnologyQingdao 266250China

Conductive grease has been considered as a potential solution in addressing electric erosion issue inside motor bearings.Understanding the conductive grease performance,especially the electric and tribological behaviour is crucial for its application.This paper combines bulk grease characterization and contact film study considering both electrical and tribological loading conditions.The results show that the electric performance for the selected conductive grease sample is electric field dependent,including both frequency and voltage amplitude.Its film impedance inside the contact area is closely related to the external electric field,running condition,and lubrication regime.The following film impedance calculation tells that not only bulk grease electric parameters,but the contact parameter,lubricant film contour and lubrication condition should be considered when performing the overall bearing electrical modelling.

关键词： Electric erosion lubricant conductivity grease film impedance

A field-deployable method for single and multiplex detection of DNA or RNA from pathogens using Cas12 and Cas13

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Science China(Life Sciences) 2022年第7期65卷 1456-1465页

作者： Lina Li Canxing Duan Jianfeng Weng Xiantao Qi Changlin Liu Xinhai Li jinjie zhu Chuanxiao Xie National Key Facility for Crop Gene Resources and Genetic Improvement Institute of Crop ScienceChinese Academy of Agricultural Sciences(CAAS)Beijing 100081 China Biotechnology Research Institute Chinese Academy of Agricultural Sciences(CAAS)Beijing 100081China

For some Cas nucleases,trans-cleavage activity triggered by CRISPR/Cas-mediated cis-cleavage upon target nucleic acid recognition has been explored for diagnostic detection.Portable single and multiplex nucleic acid-based detection is needed for crop pathogen management in agriculture.Here,we harnessed and characterized RfxCas13d as an additional CRISPR/Cas nucleic acid detection tool.We systematically characterized AsCas12a,LbCas12a,LwaCas13a,and RfxCas13d combined with isothermal amplification to develop a CRISPR/Cas nucleic acid-based tool for single or multiplex pathogen detection.Our data indicated that sufficient detection sensitivity was achieved with just a few copies of DNA/RNA targets as input.Using this tool,we successfully detected DNA from Fusarium graminearum and Fusarium verticillioides and RNA from rice black-streaked dwarf virus in crude extracts prepared in the field.Our method,from sample preparation to result readout,could be rapidly and easily deployed in the field.This system could be extended to other crop pathogens,including those that currently lack a detection method and have metabolite profiles that make detection challenging.This nucleic acid detection system could also be used for single-nucleotide polymorphism genotyping,transgene detection,and qualitative detection of gene expression in the field.

关键词： nucleic acid detection AsCas12a LbCas12a LwaCas13a RfxCas13d maize ear rot Fusarium head blight rice black-streaked dwarf virus(RBSDV)

Pollen self-elimination CRISPR–Cas genome editing prevents transgenic pollen dispersal in maize

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Plant Communications 2023年第6期4卷 212-215页

作者： Honglin Wang Xiantao Qi jinjie zhu Changlin Liu Hongwei Fan Xuecai Zhang Xinhai Li Qin Yang Chuanxiao Xie Institute of Crop Science Chinese Academy of Agricultural Sciences(CAAS)Beijing 100081China College of Agronomy Northwest A&F UniversityYangling 712100China International Maize and Wheat Improvement Center(CIMMYT) EI BatanMexico Hainan Yazhou Bay Seed Lab SanyaHainan Province 572024 China Henan Jinyuan Seed Industry Co. Ltd.ZhengzhouHenan ProvinceChina

Dear Editor,Genome editing with clustered regularly interspaced short palindromic repeats(CRISPR)–CRISPR-associated nuclease(Cas)-mediated technologies have revolutionized basic plant science and crop genetic improvement(Chen et al.,2019).Stable genetic transformation of CRISPR–Cas cassette(s)is the main approach to genome editing in planta.In many sexually reproducing plants,a major concern is the dispersal of genetically modified elements through pollen(Devos et al.,2005).Maize(Zea mays L.).

关键词： CRISPR dispersal editing

Sorption kinetics of parent and substituted PAHs for low-density polyethylene（LDPE）:Determining their partition coefficients between LDPE and water(KLDPE) for passive sampling

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Journal of Environmental Sciences 2020年第1期32卷 349-360页

作者： Pei Lei jinjie zhu Ke Pan Hong Zhang State Key Laboratory of Pollution Control and Resources Reuse School of the EnvironmentNanjing UniversityNanjing 210023China State Key Laboratory cf Environmental Aquatic Chemistry Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China Institute for Advanced Study Shenzhen UniversityShenzhen 518060China University of Chinese Academy of Sciences Beijing 100049China

Low-density polyethylene(LDPE)has been widely used as a sorbent for passive sampling of hydrophobic organic contaminants(HOCs)in aquatic environments.However,it has seen only limited application in passive sampling for measurement of freely dissolved concentrations of parent and substituted PAHs(SPAHs),which are known to be toxic,mutagenic and carcinogenic.Here,the 16 priority PAHs and some typical PAHs were selected as target compounds and were simultaneously determined by gas chromatography–mass spectrometer(GC–MS).Some batch experiments were conducted in the laboratory to explore the adsorption kinetics of the target compounds in LDPE membranes.The results showed that both PAHs and SPAHs could reach equilibrium status within19–38 days in sorption kinetic experiments.The coefficients of partitioning between LDPE film(50μm thickness)and water(KLDPE)for the 16 priority PAHs were in good agreement with previously reported values,and the values of KLDPEfor the 9 SPAHs are reported in this study for the first time.Significant linear relationships were observed,i.e.,log KLDPE=0.705×log KOW+1.534 for PAHs(R^2=0.8361,p<0.001)and log KLDPE=0.458×log KOW+3.092 for SPAHs(R^2=0.5609,p=0.0077).The selected LDPE film was also proven to meet the condition of"zero sink"for the selected target compounds.These results could provide basic support for the configuration and in situ application of passive samplers.

关键词： Low-density polyethylene(LDPE) PAHs Substituted PAHs(SPAHs) Freely dissolved concentrations Passive sampling

Establishment of an efficient seed fluorescence reporter-assisted CRISPR/Cas9 gene editing in maize

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Journal of Integrative Plant Biology 2021年第9期63卷 1671-1680页

作者： Yuanyuan Yan jinjie zhu Xiantao Qi Beijiu Cheng Changlin Liu Chuanxiao Xie Institute of Crop Science Chinese Academy of Agricultural SciencesNational Key Facility for Crop Gene Resources and Genetic ImprovementBeijing 100081China School of Life Sciences Anhui Agricultural UniversityHefei 230036China

Genome editing by clustered regularly interspaced short palindromic sequences(CRISPR)/CRISPRassociated protein 9(Cas9)has revolutionized functional gene analysis and genetic improvement.While reporter-assisted CRISPR/Cas systems can greatly facilitate the selection of genome-edited plants produced via stable transformation,this approach has not been well established in seed crops.Here,we established the seed fluorescence reporter(SFR)-assisted CRISPR/Cas9 systems in maize(Zea mays L.),using the red fluorescent Ds RED protein expressed in the endosperm(En-SFR/Cas9),embryos(Em-SFR/Cas9),or both tissues(Em/En-SFR/Cas9).All three SFRs showed distinct fluorescent patterns in the seed endosperm and embryo that allowed the selection of seeds carrying the transgene of having segregated the transgene out.We describe several case studies of the implementation of En-SFR/Cas9,Em-SFR/Cas9,and Em/En-SFR/Cas9 to identify plants not harboring the genomeediting cassette but carrying the desired mutations at target genes in single genes or in small-scale mutant libraries,and report on the successful generation of single-target mutants and/or mutant libraries with En-SFR/Cas9,Em-SFR/Cas9,and Em/En-SFR/Cas9.SFR-assisted genome editing may have particular value for application scenarios with a low transformation frequency and may be extended to other important monocot seed crops.

关键词： CRISPR/Cas9 embryo-specific reporter endosperm-specific reporter genome editing maize seed fluorescence reporter

Genome Editing Enables Next-Generation Hybrid Seed Production Technology

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Molecular Plant 2020年第9期13卷 1262-1269页

作者： Xiantao Qi Congsheng Zhang jinjie zhu Changlin Liu Changling Huang Xinhai Li Chuanxiao Xie nstitute of Crop Science Chinese Academy of Agricultural SciencesNational Key Facility for Crop Gene Resources and Genetic ImprovementBeijing 100081China Institute of Biotechnology Institute Chinese Academy of Agricultural SciencesBeijing 100081China

The next-generation hybrid seed technology enables the successful production of sortable hybrid seeds from genic male sterile(GMS)lines and maintainers;however,it requires multiple laborious and complicated steps.Here,we designed a simple next-generation hybrid seed production strategy that takes advantage of the CRISPR/Cas9 technology to create a Manipulated GMS Maintainer(MGM)system via a single transformation.Under this schema,the maize male fertility gene ZmMS26 was nullified by removal of its fifth exon using the CRISPR/Cas9 system on a vector,and a second vector carrying a functional ZmMS26 cDNA was co-transformed to restore fertility.The second vector also contains a male gametophyte inactivation gene(ZmAA1)encoding maizeα-amylase driven by the pollen-specific promoter PG47 and an endosperm fluorescent marker(DsRED)driven by the barley endosperm aleurone-specific promoter Ltp2.The derived single-copy hemizygous MGM lines bore a mutated MS26 gene,leading to complete male sterility but normal vegetative growth and grain yield.The MGM system could prevent genetic transmission of the MGM elements via male gametophytes,providing an efficient method for sorting maintainer seeds labeled by DsRED.This strategy can be extended to any GMS gene and to hybrid crops other than maize.

关键词： CRISPR/Cas9 genic male sterility manipulated maintainer ZmMS26 exon deletion

Efficiency and Inheritance of Targeted Mutagenesis in Maize Using CRISPR-Cas9

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Journal of Genetics and Genomics 2016年第1期43卷 25-36页

作者： jinjie zhu Ning Song Silong Sun Weilong Yang Haiming Zhao Weibin Song Jinsheng Lai State Key Laboratory of Agrobiotechnology and National Maize Improvement Center Department of Plant Genetics and Breeding China Agricultural University

CRISPR/Cas （clustered regularly interspaced short palindromic repeats/CR1SPR-associated proteins） is an adaptive immune system in bacteria and archaea to defend against invasion from foreign DNA fragments. Recently, it has been developed as a powerful targeted genome editing tool for a wide variety of species. However, its application in maize has only been tested with transiently expressed somatic cells or with a limited number of stable transgenic To plants. The exact efficiency and specificity of the CRISPR/Cas system in the highly complex maize genome has not been documented yet. Here we report an extensive study of the well-studied type II CRISPR-Cas9 system for targeted genome editing in maize, with the codon-optimized Cas9 protein and the short non-coding guide RNA generated through a functional maize U6 snRNA promoter. Targeted gene mutagenesis was detected for 90 loci by maize protoplast assay, with an average cleavage efficiency of 10.67 %. Stable knockout transformants for maize phytoene synthase gene （PSYI） were obtained. Mutations occurred in germ ceils can be stably inherited to the next generation. Moreover, no off-target effect was detected at the computationally predicted putative off-target loci. No significant difference between the transcriptomes of the Cas9 expressed and non-expressed lines was detected. Our results confirmed that the CRISPR-Cas9 could be successfully applied as a robust targeted genome editing system in maize.

关键词： CRISPR-Cas9 Targeted mutagenesis Heritability Maize

基于模态驱动分析方法的桥梁颤振模态影响机理

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土木工程学报 2024年第3期57卷 81-92页

作者：朱进波杨詠昕徐浩骏张晋杰葛耀君同济大学土木工程防灾国家重点实验室上海200092

通过定量描述各阶模态及其分布特性在颤振演化过程中的影响,研究了多阶模态耦合导致的桥梁颤振三维效应。首先,根据系统模态中固有模态间的激励-反馈机制推导出能够反应各阶模态参与贡献的系统阻尼和刚度解析解,建立了适用于三维颤振机... 详细信息

通过定量描述各阶模态及其分布特性在颤振演化过程中的影响,研究了多阶模态耦合导致的桥梁颤振三维效应。首先,根据系统模态中固有模态间的激励-反馈机制推导出能够反应各阶模态参与贡献的系统阻尼和刚度解析解,建立了适用于三维颤振机理分析的模态驱动分析方法。其次,对桥梁整体系统阻尼沿着跨向进行泰勒展开,建立了跨向节段与气动性能间的定量关系,使得该方法能够量化各阶模态跨向分布特性的影响。然后,以主跨径为500~1500m的悬索桥为例,系统地研究了模态的参与及其分布特性对颤振性能的影响。最后,通过比对二维和三维分析结果,揭示了三维效应的影响及其产生原因。研究结果表明:由于基础竖弯和扭转振型不可能完全相似,三维两模态结果必然大于二维分析结果;随着风速提升二阶正对称竖弯模态先提供负向阻尼后提供正向阻尼,其对颤振性能的影响取决于自身频率与系统颤振频率的比值;约70%的梁段贡献了绝大多数的气动阻尼。

关键词：三维颤振悬索桥模态耦合三维效应跨向分布特性

OS1 functions in the allocation of nutrients between the endosperm and embryo in maize seeds

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Journal of Integrative Plant Biology 2019年第6期61卷 706-727页

作者： Weibin Song jinjie zhu Haiming Zhao Yingnan Li Jiangtao Liu Xiangbo Zhang Liangliang Huang Jinsheng Lai State Key Laboratory of Agrobiotechnology and National Maize Improvement Center Department of Plant Genetics and Breeding ChinaAgricultural University

Uncovering the genetic basis of seed develop-ment will provide useful tools for improving both crop yield and nutritional value, However, the genetic regulatory networks of maize (Zea mays) seed development remain largely unknown. The maize opaque endosperm and small germ 1 (osl) mutant has opaque endosperm and a small embryo,Here, we cloned OSi1 and show that it encodes a putative transcription factor containing an RWP-RK domain-Transcriptional analysis indicated that OSi1 expression is elevated in early endosperm development, especially in the basal endosperm transfer layer (BETL), conducting zone (CZ), and central starch endospcrm (CSE) cells. RNA sequencing (RNA-Seq) analysis of the osi mutant revealed sharp downregulation of certain genes in specific cell types, including ZmMRP-1 and Megl in BETL cells and a majority of zein-and starch-related genes in CSE cells. Using a haploid induction system, we show that wild-type endosperm could rescue the smaller size of osi embryo, which suggests that nutrients are allocated by tho wild type endosperm. Therefore, our dsta imply that the network regulated by 051 accomplishes a key step in nutrient allocation between endosperm and embryo within maize seeds. Identification of this network will help uncover the mechanisms regulating the nutritional balance between endosperm and embryo.

关键词： 0S1 functions the allocation of nutrients between the endosperm and embryo in maize seeds^FA