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Induction of apoptosis in purified animal and plant nuclei by Xenopus egg extracts

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Cell Research 1999年第2期9卷 79-90页

作者： JIANG ZheNG FAN SHAN ZHU YING LI SUN zhong he zhai (College of Life Sciences, Peking University, Beijing 100871, China) College of Life Sciences Peking University Beijing China

We have developed a cell-free system that can trigger the nuclei purified from mouse liver and suspensioncultured carrot cells to undergo apoptosis as defined by the formation of apoptotic bodies and nucleosomal DNA fragments. The effects of different divalent cations and cycloheximide on DNA cleavage in this system were *** fact that nuclei of plant cells can be induced to undergo apoptosis in a cell-free animal system suggests that animals and plants share a common signal transduction pathway triggering in the initiation stage of apoptosis.

关键词： Apoptosis Xenopus laevis cell-free carrot mouse dATP

LDFF,the large molecular weight DNA fragmentation factor,is responsible for the large molecular weight DNA degradation during apoptosis in Xenopus egg extracts

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Cell Research 2004年第2期14卷 134-140页

作者： Zhi Gang LU, Chuan Mao ZHANG~*, zhong he zhai~* Department of Cell Biology and Genetics, College of Life Sciences, Peking University, Beijing 100871, China. Department of Cell Biology and Genetics College of Life Sciences Peking University Beijing China

DNA degradation is a biochemical hallmark in apoptosis. It has been demonstrated in many cell types that there are two stages of DNA fragmentation during the apoptotic execution. In the early stage, chromatin DNA is cut into large molecular weight DNA fragments, although the responsible nuclease(s) has not been recognized. In the late stage, the chromatin DNA is cleaved further into short oligonucleosomal fragments by a well-characterized nuclease in apoptosis, the caspase-activated DNase (CAD/DFF40). In this study, we demonstrate that large molecular weight DNA fragmentation also occurs in Xenopus egg extracts in apoptosis. We show that the large molecular weight DNA fragmentation factor (LDFF) is not the Xenopus CAD homolog XCAD. LDFF is activated by caspase-3. The large molecular weight DNA fragmentation activity of LDFF is Mg2+-dependent and Ca2+-independent, can occur in both acidic and neutral pH conditions and can tolerate 45℃ treatment. These results indicate that LDFF in Xenopus egg extr

关键词： apoptosis caspase-activated DNase (CAD) large molecular weight DNA fragmentation factor (LDFF).

Association of DNA with nuclear matrix in in vitro assembled nuclei induced by rDNA from Tetrahymena shanghaiensis in Xenopus egg extracts

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Cell Research 1997年第1期7卷 107-117页

作者： CheN YING BO ZHANG XIU FEN LI zhong he zhai(Department of Cell Biology and Genetics, College of Life Sciences, Peking University, Beijing 100871) Department of Cell Biology and Genetics College of Life Sciences Peking University Beijing

The nuclei assembled from exogenous DNA or chromatin in egg extracts resemble their in vivo counterparts in many aspects. However, the distribution pattern of DNA in these nuclei remains unknown. We introduced rDNA from the macronuclei of Tetrabymena into Xenopus cellfree extracts to examine the association of specific DNA sequences with nuclear matrix (NM) in the nuclei assembled in vitro. Our previous works showed the 5'NTS (nontranscription sequences) of the rDNA specifically bind to the NM system in the macronuclei. We show now the rDNA could induce chromatin assembly and nuclear formation in Xenopus cell-free system. When we extracted the NM system and compared the binding affinity of different regions of rDNA with the NM system, we found that the 5'NTS still hold their binding affinity with insoluble structure of the assembled nuclei in the extracts of Xenopus eggs.

关键词： Nuclear assembly nuclear matrix Xenopus egg extracts Tetrahymena rDNA

Structural components of the nuclear body in nuclei of Allium cepa cells

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Cell Research 2001年第1期11卷 68-73页

作者： TAO WEI, CHANG HUI YAN, TAO CAI, SHUI HAO, zhong he zhai (College of Life Sciences, Peking University, Beijing 100871, China) (Institute of Genetics and Cytology, Northeast Normal University, Changchun Jilin 130024, China) College of Life Sciences Peking University Beijing China Institute of Genetics and Cytology Northeast Normal University Changchun Jilin China

Nuclear bodies have long been noted in interphase nuclei of plant cells, but their structural component, origin and fUnction are still unclear by now. The present work showed in onion cells the nuclear bodies appeared as a spherical structure about 0.3 to 0.8 μm in diameter. They possibly were formed in nucleolus and subsequently released, and entered into nucleoplasm. Observation through cytochemical staining method at the ultrastructural level codeined that nuclear bodies consisted of ribonucleoproteins (RNPs) and silver-stainable proteins. Immunocytochemical results revealed that nuclear bodies contained no DNA and ribosomal gene transcription factor (UBF). Based on these data, we suggested that nuclear bodies are not related to the ribosome or other gene transcription activities, instead they may act as subnuclear structures for RNPs transport from nucleolus to cytoplasm, and may also be involved in splicing of pre-mRNAs.

关键词： Nuclear body structural component ribonucleoproteins nucleolus Allium cepa.

Uptrend of the Western North Pacific Tropical Cyclone Outflow height during 1959-2021

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Journal of Meteorological Research 2024年第2期38卷 339-350页

作者： Yuan SUN Zhihao FENG Wei zhong Panmao zhai Yanluan LIN Shuo LYU College of Advanced Interdisciplinary Studies National University of Defense TechnologyNanjing 211100 College of Meteorology and Oceanography National University of Defense TechnologyChangsha 410073 State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesChina Meteorological AdministrationBeijing 100081 Ministry of Education Key Laboratory for Earth System Modeling Department of Earth System ScienceTsinghua UniversityBeijing 100084

Relatively little is known about the impact of global warming on the tropical cyclone(TC)outflow,despite its large contribution to TC *** this study,based on the International Best Track Archive for Climate Stewardship(IBTrACS)dataset and ERA5 reanalysis data,we show that the TC outflow height has risen significantly(48.20±22.18 m decades-1)in the past decades(1959-2021)over the western North Pacific,and the rising trend tends to be sharper for stronger TCs(the uptrend of severe typhoon is 61.09±40.92 m decades-1).This rising trend of the outflow height explains the contradiction between the decrease trend of the TC outflow temperature and the increase trend of the atmospheric troposphere ***,possible contribution of the TC outflow height uptrend to TC intensity has also been *** results show that the rise of outflow height leads to the decrease of outflow temperature,and thus an increased difference between underlying sea surface temperature(SST)and TC outflow temperature,which eventually favors the increase of TC intensity.

关键词： tropical cyclone outflow height global warming western North Pacific

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High quality repair of osteochondral defects in rats using the extracellular matrix of antler stem cells

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World Journal of Stem Cells 2024年第2期16卷 176-190页

作者： Yu-Su Wang Wen-Hui Chu Jing-Jie zhai Wen-Ying Wang zhong-Mei he Quan-Min Zhao Chun-Yi Li Institute of Antler Science and Product Technology Changchun Sci-Tech UniversityChangchun 130000Jilin ProvinceChina College of Chinese Medicinal Materials Jilin Agricultural UniversityChangchun 130118Jilin ProvinceChina School of Life Science Taizhou UniversityTaizhou 318000Zhejiang ProvinceChina Department of Oral Implantology Hospital of StomatologyJilin UniversityChangchun 130000Jilin ProvinceChina

BACKGROUND Cartilage defects are some of the most common causes of *** lesions caused by inflammation,trauma or degenerative disease normally result in osteochondral *** studies have shown that decellularized extracellular matrix(ECM)derived from autologous,allogenic,or xenogeneic mesenchymal stromal cells(MSCs)can effectively restore osteochondral *** To determine whether the decellularized ECM of antler reserve mesenchymal cells(RMCs),a xenogeneic material from antler stem cells,is superior to the currently available treatments for osteochondral *** We isolated the RMCs from a 60-d-old sika deer antler and cultured them in vitro to 70%confluence;50 mg/mL L-ascorbic acid was then added to the medium to stimulate ECM *** sheets of adipocyte-derived MSCs(aMSCs)and antlerogenic periosteal cells(another type of antler stem cells)were used as the *** weeks after ascorbic acid stimulation,the ECM sheets were harvested and applied to the osteochondral defects in rat knee *** The defects were successfully repaired by applying the *** highest quality of repair was achieved in the RMC-ECM group both in vitro(including cell attachment and proliferation),and in vivo(including the simultaneous regeneration of well-vascularized subchondral bone and avascular articular hyaline cartilage integrated with surrounding native tissues).Notably,the antler-stem-cell-derived ECM(xenogeneic)performed better than the aMSC-ECM(allogenic),while the ECM of the active antler stem cells was superior to that of the quiescent antler stem *** Decellularized xenogeneic ECM derived from the antler stem cell,particularly the active form(RMC-ECM),can achieve high quality repair/reconstruction of osteochondral defects,suggesting that selection of decellularized ECM for such repair should be focused more on bioactivity rather than kinship.

关键词： Osteochondral defect repair Mesenchymal stem cells Extracellular matrix Decellularization Antler stem cells Reserve mesenchymal cells Xenogeneic

Uncovering the magnetic response of open-shell graphene nanostructures on metallic surfaces at different doping levels

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Science China(Physics,Mechanics & Astronomy) 2024年第2期67卷 142-148页

作者： Zengfu Ou Jun Wang Jihai Zhang Yukang Ding Shenwei Chen Wenya zhai Jingcheng Li Dingyong zhong Donghui Guo School of Physics Sun Yat-sen UniversityGuangzhou 510275China Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices School of PhysicsSun Yat-sen UniversityGuangzhou 510275China State Key Laboratory of Optoelectronic Materials and Technologies Sun Yat-sen UniversityGuangzhou 510275China College of Chemical Engineering Zhejiang University of TechnologyHangzhou 310014China

Open-shell graphene nanostructures(GNs)are promising candidates for future spintronics and quantum *** progress based on on-surface synthetic approach has successfully created such GNs on metallic ***,the doping effect of metallic surfaces is inevitably present and can significantly tune their electronic and magnetic ***,we investigate the zigzag end states of open-shell 7-armchair graphene nanoribbons(7-AGNRs)on Au(111),Au(100)and Ag(111)*** with the manipulation of a scanning tunneling microscope,we demonstrate that the end states can be tuned from empty states to singly occupied states and to doubly occupied states by substrate ***,the singly occupied states can be finely tuned,with the occupancy number of the states and related magnetic behaviors uncovered by experiments at different temperatures and magnetic *** results provide a comprehensive study of the magnetic response of open-shell GNs on metallic surfaces at different doping levels.

关键词： open-shell graphene nanostructures magnetic response metallic substrate doping Kondo resonance scanning tunneling microscopy/spectroscopy

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Giant piezotronic effect in ferroelectric field effect transistor

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Nano Research 2024年第9期17卷 8465-8471页

作者： Haiming Zhang Mengshuang Chi Shidai Tian Tian Liang Jitao Liu Xiang Zhang Lingyu Wan zhong Lin Wang Junyi zhai Center on Nanoenergy Research School of Physical Science&TechnologyGuangxi UniversityNanning 530004China Beijing Key Laboratory of Micro-Nano Energy and Sensor Center for High-Entropy Energy and SystemsBeijing Institute of Nanoenergy and NanosystemsChinese Academy of SciencesBeijing 101400China School of Nanoscience and Engineering University of Chinese Academy of ScienceBeijing 100049China School of Electronic Science and Engineering University of Electronic Science and Technology of ChinaChengdu 610054China Georgia Institute of Technology AtlantaGA 30332USA

The piezotronics effect utilizes a piezopotential to modulate and control current in *** materials,as a type of piezoelectric materials,possess piezoelectric coefficients that are significantly larger than those found in conventional piezoelectric ***,we propose a strain modulated ferroelectric field-effect transistor(St-FeFET)utilizing external strain instead of gate voltage to achieve ferroelectric modulation,which eliminates the need for gate *** applying a very small strain(0.01%),the St-FeFET can achieve a maximum on-off current ratio of 1250%and realizes a gauge factor(GF)of 1.19×10^(6),which is much higher than that of conventional strain *** work proposes a new method for realizing highly sensitive strain sensors and presents innovative approaches to the operation methods of ferroelectric field-effect transistors as well as potential applications for coupling of strain sensors and various devices across different fields.

关键词： ferroelectric field-effect transistors piezotronics [Pb(Mg_(1/3)Nb_(2/3))O_(3)]_((1-x)^(-))[PbTiO_(3)]_(x)(PMN-PT) strain sensors

Overexpression of the peroxidase gene ZmPRX1 increases maize seedling drought tolerance by promoting root development and lignification

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The Crop Journal 2024年第3期12卷 753-765页

作者： Xiuzhen zhai Xiaocui Yan Tinashe Zenda Nan Wang Anyi Dong Qian Yang Yuan zhong Yue Xing Huijun Duan State Key Laboratory of North China Crop Improvement and Regulation Key Laboratory of Crop Germplasm Resources in North China Ministry of EducationCollege of AgronomyHebei Agricultural UniversityBaoding 071001HebeiChina

Drought is a main abiotic stress factor hindering plant growth,development,and crop ***,it is crucial to understand the mechanisms by which plants cope with drought ***,the function of the maize peroxidase gene ZmPRX1 in drought stress tolerance was investigated by measurement of its expression in response to drought treatment both in a ZmPRX1 overexpression line and a mutant *** higher root lignin accumulation and seedling survival rate of the overexpression line than that of the wild type or mutant support a role for ZmPRX1 in maize drought tolerance by regulating root development and ***,yeast one-hybrid,Dule luciferase and ChIP-qPCR assays showed that ZmPRX1 is negatively regulated by a nuclear-localized ZmWRKY86 transcription *** gene could potentially be used for breeding of drought-tolerant cultivars.

关键词： Drought tolerance Maize ZmPRX1 Root development Lignin biosynthesis

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