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Sub-molecular features of single proteins in solution resolved with scanning tunneling microscopy

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Nano Research 2016年第9期9卷 2551-2560页

作者： Jihao Wang Lei Zhang Chen Hu Qingsong Liu Yubin Hou Xin Zhang qingyou lu High Magnetic Field Laboratory Chinese Academy of Sciences and University of Science and Technology of ChinaHefei 230026China Hefei National Laboratory for Physical Sciences at the Microscale University of Science and Technology of ChinaHefei 230026China Collaborative Innovation Center of Advanced Microstructures Nanjing UniversityNanjing 210093China

Scanning tunneling microscopy (STM) can be used to image individual biological molecules, such as proteins, in vacuum or air. This requires sample dehydration and thus may not reflect the native state of the molecule. Extensive efforts have been made to image single proteins in solution using STM; however, the images have revealed only round or oval shapes with no sub-molecular details. Here, we present the sub-molecular features of streptavidin proteins under physiological conditions using a homebuilt low-leakage-current and highstability liquid phase STM. The N-lobe, C-lobe, and C-terminal tail of the epidermal growth factor receptor kinase domains were also resolved in solution. Our results demonstrate that the structure, morphology, and dynamics of a protein molecule can be examined under physiological conditions by the STM. [Figure not available: see fulltext.] © 2016, Tsinghua University Press and Springer-Verlag Berlin Heidelberg.

关键词： liquid-phase scanning tunneling microscopy (STM) STM imaging under physiological conditions protein molecule sub-molecular resolution

Effects of 3.7 T-24.5 T high magnetic fields on tumor-bearing mice

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Chinese Physics B 2018年第11期27卷 649-658页

作者： Xiaofei Tian Ze Wang Lei Zhang Chuanying Xi Li Pi Ziping Qi qingyou lu Xin Zhang High Magnetic Field Laboratory Key Laboratory of High Magnetic Field and Ion Beam Physical Biology Hefci Institutes of Physical Science Chinese Academy of Sciences Hefei 230031 China Institute of Physical Science and Information Technology Anhui University Hefei 230601 China Hefei National Laboratory for Physical Sciences at Microscale University of Science and Technology of China Hefei 230026 China Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions Hefei 230031 China

Since high magnetic field（MF） intensity can improve the image quality and reduce magnetic resonance imaging（MRI） acquisition time, the field intensity of MRIs has continued to increase over the past few decades. Although MRIs in most current hospitals are 0.5 T–3 T, there are preclinical studies have been carried out using 9.4 T MRI, and engineers are also putting efforts on building MRIs with even higher MFs. However, the accompanied safety issue of high-field MRIs is an emergent question to address before their clinical applications. In the meantime, the static magnetic field（SMF） has been shown to inhibit tumor growth in previous studies. Here, we investigated both the safety issue and the anti-tumor potentials of 3.7 T–24.5 T SMFs on GIST-T1 gastrointestinal stromal tumor-bearing nude mice. We followed up the mice three weeks after their exposure to high SMF and found that none of the mice died or had severe organ damage, except for slightly decreased food intake, weight gain, and liver function. Moreover, the tumor growth was inhibited by 3.7 T–24.5 T SMFs（up to ～54%）. It is interesting that the effects are more dependent on MF gradient than intensities, and for the same gradient and intensity, mice responded differently to hypogravity and hypergravity conditions. Therefore, our study not only demonstrated the safeness of high SMFs up to 24.5 T on mice but also revealed their anti-tumor potentials in the future.

关键词： static magnetic field (SMF) high magnetic field (MF) tumor magnetic field gradient

MicroRNA let-7 targets BmCDK1 to regulate cell proliferation and endomitosis of silk gland in the silkworm,Bombyx mori

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Insect Science 2024年第4期31卷 1026-1040页

作者： Wei Wang Linshengzhe Ji Xinyuan Jing Ping Zhao qingyou Xia Integrative Science Center of Germplasm Creation in Western China(Chongqing)Science City Biological Science Research CenterSouthwest UniversityChina Key Laboratory for Germplasm Creation in Upper Reaches of the Yangtze River Ministry of Agriculture and Rural AffairsChongqingChina Engineering Laboratory of Sericultural and Functional Genome and Biotechnology Development and Reform CommissionChongqingChina

MicroRNAs play critical roles in multiple developmental processes in *** previous study showed that CRISPR/Cas9-mediated knock down of the microRNA let-7 in silkworms increased the size of larvae and silk glands,thereby improving the silk production *** this study,we elucidate the molecular mechanism underlying of let-7 regulates *** of differentially expressed genes in response to let-7 knock down revealed enrichment of pathways associated with cell proliferation and DNA ***-7 dysregulation affected the cell cycle and proliferation of the Bombyx mori cell line ***-luciferase and target site mutation assays showed that BmCDK1 is a direct target gene of let-7,with only 1 binding site on its 3′-untranslated *** interference of BmCDK1 inhibited cell proliferation,but this effect was counteracted by co-transfection with let-7 ***,let-7 knock down induced BmCDK1 expression and promoted cell proliferation in multiple tissues,and further induced endomitosis in the silk gland in *** down of BmCDK1 resulted in abnormal formation of a new epidermis,and larval development was arrested at the 2nd or 3rd molt *** together,our results demonstrated that BmCDK1 is a novel target of let-7 in cell fate determination,possessing potential for improving silk yield in silkworm.

关键词： BmCDKI CRISPR/Cas9 cell proliferation let-7 silkworm

Magnetic effects on EGFR kinase domain revealed with liquid-phase STM at single-molecule scale

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Magnetic effects on EGFR kinase domain revealed with liquid-...

Molding simulation of airfoil foam sandwich structure and interference optimization of foam-core

中国化学会第十三届全国分析化学年会

作者： Jihao Wang Jing Zhang Wenjie Meng qingyou lu High Magnetic Field Laboratory of the Chinese Academy of Sciences University of Science and Technology of China

Magnetic effects of proteins have been proposed decades ago, the behavior of isolated proteins in magnetic fields has not been directly observed [1-3]. Using the homebuilt liquid-phase scanning tunneling microscope（STM）, we investigated the native state of Epidermal Growth Factor Receptor（EGFR） molecules under physiological conditions systematically. Sub-molecular resolution images of single EGFR molecule and dynamic formation process of EGFR dimmers were obtained for the first time. Furthermore, we observed orientation of EGFR molecules in response to magnetic fields. This may interrupt inter-molecular interactions between EGFR monomers, which are critical for their activation. Our results will support the further investigations in understanding of the biological effects of magnetic fields at single-molecule scale.

关键词： scanning tunneling microscope EGFR magnetic effects

来源： cnki会议评论

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Chinese Journal of Aeronautics 2024年第10期37卷 325-338页

作者： Qianying CEN Zeyang XING qingyou WANG Lili LI Zhigang WANG Zhanjun WU Ling LIU School of Aerospace Engineering&Applied Mechanics Tongji UniversityShanghai 200092China AVIC Harbin Aircraft Industry Group Co.Ltd Harbin 150066China School of Aeronautics and Astronautics Dalian University of TechnologyDalian 116024China

During the Co-Cure Molding(CCM)of airfoil foam sandwich structure,it is challenging to avoid collapse of foam core at the trailing ***,an Equal Proportional Thickening(EPT)method is proposed to optimize the interference of polymethacrylimide(PMI)foam core during the CCM ***,based on some basic parameters of composite skin and foam core obtained by experiments or multi-scale simulations,a thermal-curing-mechanical coupling analysis for the CCM of foam sandwich structure is performed and the results show that the maximum stress within foam core occurs at the completion of mold-closing,which tends to decrease during the subsequent CCM ***,the foam core is thickened by traditional equidistant-thickening method,and the simulation reveals that the foam core at the trailing edge tends to collapse because of stress ***,if the foam core is thickened by the proposed EPT method,the mold-closing caused collapse at the trailing edge can be effectively avoided,and a thickening ratio range of 0.6%–2.0%is obtained,which is further proved by practical ***,the interference design scheme proposed can ensure the molding quality and effectively reduce the scrap of molded products.

关键词： Airfoil foam sandwich structure Polymethacrylimide(PMI)foam Interference Co-curing Molding simulation

Genome-wide CRISPR screening reveals key genes and pathways associated with 20-hydroxyecdysone signal transduction in the silkworm(Bombyx mori)

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Insect Science 2024年第1期31卷 47-58页

作者： Hao Sun Jingya Chen Ruolin Wang Dan Liu Na Zhang Tong Zhang Ling Jia Sanyuan Ma qingyou Xia State Key Laboratory of Silkworm Genome Biology Southwest UniversityChongqingChina Biological Science Research Center Southwest UniversityChongqingChina

Metamorphosis is a complex developmental process involving multiple pathways and a large number of genes that are regulated by juvenile hormone(JH)and 20-hydroxyecdysone(20E).Despite important progress in understanding various aspects of silkworm biology,the hormone signaling pathway in the silkworm remains poorly ***-wide screening using clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated protein 9(Cas9)-based libraries has recently emerged as a novel method for analyzing genome function,enabling further research into essential genes,drug targets,and virus-host ***,we constructed a genome-wide CRISPR/Cas9-based library of the silkworm(Bombyx mori)and successfully revealed the genes involved in biotic or abiotic stress factor *** this study,we used our silkworm CRISPR library and large-scale genome-wide screening to analyze the key genes in the silkworm 20E signaling pathway and their mechanisms of *** annotation showed that 20E regulates key proteins in processes that mainly occur in the cytoplasm and *** enrichment analysis showed that 20E can activate phosphorylation and may affect innate immunity,interfere with intracellular nutrition and energy metabolism,and eventually cause cell *** screening results were experimentally validated by generating cells with knockout alleles of the relevant genes,which had increased tolerance to *** findings provide a panoramic overview of signaling in response to 20E in the silkworm,underscoring the utility of genome-wide CRISPR mutant libraries in deciphering hormone signaling pathways and the mechanisms that regulate metamorphosis in insects.

关键词： CRISPR/Cas9 CRISPR library screening ecdysone 20E signal transduction silkworm whole genome editing

High-efficiency prediction method for helicopter global/ground noise based on near-field acoustic holography

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Chinese Journal of Aeronautics 2024年第7期37卷 271-284页

作者： Mengxue SHAO Yang lu Xice XU Jiaxin lu National Key Laboratory of Helicopter Aeromechanics Nanjing University of Aeronautics and AstronauticsNanjing 210016China

Noise reduction program design is an effective approach that relies on efficient noise prediction for reducing ground noise during *** existing noise prediction methods have the limitations of being computationally expensive or only applicable to *** this paper,a High-Efficiency Prediction Method(HEPM)for helicopter global/ground noise based on near-field acoustic holography is *** HEPM can predict the global noise based on acoustic modal analysis and has the advantages of high prediction accuracy and low time *** process is given as follows:firstly,the rotor noise on the holographic surface in the specified flight is obtained by simulations or ***,the global noise model,which maps time-domain noise to acoustic modes,is established based on near-field acoustic holography and Fourier acoustic analysis ***,combined with acoustic modal amplitude,the model established enables efficiently predicting the global/ground noise in the corresponding flight *** verify the accuracy of the prediction method,a simulation study is conducted in hovering and forward flight states using a model helicopter with a 2-meter rotor and Rotor Body Interaction(ROBIN)*** comparison of HEPM with numerical results shows that the average prediction errors of the global and ground noise are less than 0.3 dB and 0.2 dB,*** a region containing 100000 observers,the computation time of the HEPM is only one-fifth of that of the acoustic hemisphere method,demonstrating the rapidity of the proposed method.

关键词： Helicopter Rotor noise prediction Noise abatement procedure design Acoustic modal analysis Near-field acoustic holography

Collective Molecular Machines: Multidimensionality and Reconfigurability

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Nano-Micro Letters 2024年第8期16卷 309-340页

作者： Bin Wang Yuan lu Department of Chemical Engineering Tsinghua UniversityBeijing 100084People’s Republic of China Key Laboratory of Industrial Biocatalysis Ministry of EducationTsinghua UniversityBeijing 100084People’s Republic of China

Molecular machines are key to cellular activity where they are involved in converting chemical and light energy into efficient mechanical *** the last 60 years,designing molecular structures capable of generating unidirectional mechanical motion at the nanoscale has been the topic of intense *** progress has been made,attributed to advances in various fields such as supramolecular chemistry,biology and nanotechnology,and ***,individual molecular machines are only capable of producing nanometer work and generally have only a single *** order to address these problems,collective behaviors realized by integrating several or more of these individual mechanical units in space and time have become a new *** this review,we comprehensively discuss recent developments in the collective behaviors of molecular *** particular,collective behavior is divided into two *** is the appropriate integration of molecular machines to efficiently amplify molecular motions and deformations to construct novel functional *** other is the construction of swarming modes at the supramolecular level to perform nanoscale or microscale *** discuss design strategies for both modes and focus on the modulation of features and ***,in order to address existing challenges,the idea of transferring experience gained in the field of micro/nano robotics is presented,offering prospects for future developments in the collective behavior of molecular machines.

关键词： Molecular machines Collective control Collective behaviors DNA Biomolecular motors

Soil inorganic amendments produce safe rice by reducing the transfer of Cd and increasing key amino acids in brown rice

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Journal of Environmental Sciences 2024年第2期136卷 121-132页

作者： Fanyi Kong Shenggao lu Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment Key Laboratory of Environmental Remediation and Ecosystem HealthMinistry of EducationCollege of Environmental and Resource SciencesZhejiang UniversityHangzhou 310058China

The digestibility of cadmium(Cd)in brown rice is directly related to amino acid metabolism in rice and human *** our field study,three kinds of alkaline calcium-rich soil inorganic amendments(SIAs)at three dosages were applied to produce safe rice and improve the quality of rice in Cd-contaminated *** the increased application of SIA,Cd content in iron plaque on rice root significantly increased,the transfer of Cd from rice root to grain significantly decreased,and then Cd content in brown rice decreased *** vitro digestibility of Cd in brown rice was estimated by a physiologically based extraction *** showed that more than 70%of Cd in brown rice could be digested by simulated gastrointestinal *** on the total and digestible Cd contents in brown rice to evaluate the health risk,the application of 2.25 ton SIA/ha could produce safe rice in acidic slightly Cd-contaminated paddy *** amino acids(AAs)in brown rice were determined by high-performance liquid *** contents of 5 key AAs(KAAs)that actively respond to environmental changes increased significantly with the increased application of *** structural equation model indicated that KAAs could be affected by the Cd translocation capacity from rice root to grain,and consequently altered the ratio of indigestible Cd in brown *** formation of indigestible KAAs-Cd complexes by combining KAAs(phenylalanine,leucine,histidine,glutamine,and asparagine)with Cd in brown rice could be considered a potential mechanism for reducing the digestibility of Cd.

关键词： Cadmium digestibility Soil inorganic amendments Safe rice Amino acid Priming effect Health risk