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Integration of Cytological Features with Molecular and Epigenetic Properties of Rice Chromosome 4

Molecular Plant 2008年第5期1卷 816-829页

作者： Ben-Liang Yin lan GUO Dong-Fen Zhang William Terzaghi Xiang-Feng wang Ting-Ting Liu Hang He Zhu-Kuan Cheng xing wang Deng National Institute of Biological Sciences Beijing 102206 China Peking-Yale Jo-int Research Center-fo-r-Plant'Molecular-an-dAgrobiotechnology College of Life Sciences Peking University Beijing 100871 China Institute of Genetics and Developmental Biology Chinese Academy of Sciences Beijing 100101 China Department of Molecular Cellular and Developmental Biology Yale University New Haven CT 06520-8104 USA Department of Biology Wilkes University Wilkes-Barre PA 18766 USA

It has been reported that rice chromosome 4 has eight major heterochromatic knobs within the heterochromatic half and that this organization correlates with chromosomal-level transcriptional activity. To better understand this chromosomal organization, we created a model based on the statistical distribution of various types of gene models to divide chromosome 4 into 17 euchromatic and heterochromatic regions that correspond with the cytological staining. Fluorescence in-situ hybridization （FISH） experiments using a set of bacterial artificial chromosome （BAC） clones from chromosome 4 placed all 18 clones in the region predicted by the model. Elevated levels of H3K4 di- and tri-methylation detected by chromatin-immunoprecipitation （CHIP） on chip were correlated with euchromatic regions whereas lower levels of these two modifications were detected in heterochromatic regions. Small RNAs were more abundant in the heterochromatic regions. To validate these findings, H3K4 trimethylation, H3K9 acetylation, H4K12 acetylation, and H3K9 di- and tri-methylation of 19 individual genes were measured by ChlP-PCR. Genes in heterochromatic regions had elevated H3K9 di- and tri-methylation while genes in euchromatic regions had elevated levels of the other three modifications. We also assayed cytosine methylation of these genes using the restriction enzymes McrBC, Hapll, and Msp I. This analysis indicated that cytosines of transposable elements and some genes located in heterochromatic regions were methylated while cytosines of the other genes were unmethylated. These results suggest that local transcriptional activity may reflect the organization of the corresponding part of the chromosome. They also indicate that epigenetic regulation plays an important role in correlating chromosomal organization with transcriptional activity.

关键词： chromosome organization FISH histone modification DNA methylation.

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Crystalline Size Effects on Texture Coefficient,Electrical and Optical Properties of Sputter-deposited Ga-doped ZnO Thin Films

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Journal of Materials Science & Technology 2015年第2期31卷 175-181页

作者： Yaqin wang Wu Tang lan Zhang State Key Laboratory of Electronic Thin Films and Integrated Devices University of Electronic Science and Technology of China State Key Laboratory for Mechanical Behavior of Materials Xi'an Jiaotong University

C-axis oriented Ga-doped ZnO(GZO) films with various thicknesses were deposited on glass substrate by radio frequency(RF) magnetron sputtering. The dependence of crystal structure,electrical,and optical properties of the GZO films on crystalline size were systematically studied. The results showed that the texture coefficient of (002) peak (TC(002)) decreases with increasing crystalline size. The Hall mobility m was reciprocal to electron effective mass and the fitted relaxation time s was 0.11±0.01 ms. With the increase of average crystalline size,the resistivity increased slightly,which is caused by the competition of (002) and(101) plane,introducing in some defects and leading to carrier density reduction. The optical band gap was in the range from 3.454 to 3.319 eV with increasing crystalline size from 26.96 to 30.88 nm,showing a negative relationship. The dependence of optical band gap (Eopg) on the crystalline size(R) can be qualitatively explained by a quantum confinement effect. The relationship between Eopg and R of GZO films suggests that tuning up optical properties for desired applications can be achieved by controlling the crystalline size.

关键词： Ga-doped ZnO film Crystalline size Texture coeffic

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Elevational diversity gradients across seed plant taxonomic levels in the lancang River Nature Reserve： role of temperature, water and the mid-domain effect

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Journal of Forestry Research 2018年第4期29卷 1110-1116页

作者： Jie Gao xing Zhang Zhifeng Luo Junjie lan Yanhong Liu Forestry College of Beijing Forestry University No. 35 Qinghua East Road Beijing 100083 People's Republic of China Powerchina Kunming Engineering Corporation Limited No 115 Renmin East Road Kunming 650051 People's Republic of China

It remains unclear whether the elevational diversity gradients observed in seed plants across different taxonomic levels （family, genus, and species） are driven by the same macro-environmental variables. In this study, seed plant elevational distribution data from the lancang River Nature Reserve （Yunnan, China） were used to investigate spatial patterns in diversity and their environ- mental correlates, comparing across taxonomic levels. Environmental variables included energy availability, climate seasonality and environmental heterogeneity. All taxonomic levels （family, genus, and species） were found to have strong elevational richness gradients, with the strength of the gradient weakening at higher taxonomic levels. Spatial patterns in richness were explained by a combination of contemporary environmental variables and the mid-domain effect at all taxonomic levels. The independent effects of temperature- and precipitation-related variables were similar in explaining geographical patterns of family, genus and species richness. Energy, seasonality and heterogeneity variables influenced seed plant spatial richness at different taxonomic levels in similar ways.

关键词： Elevational diversity gradients lancang River Nature Reserve Energy availability Climate seasonality Environmental heterogeneity

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New geographic distribution and molecular diversity of Citrus chlorotic dwarf-associated virus in China

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Journal of Integrative Agriculture 2022年第1期21卷 293-298页

作者： YANG Zhen ZHANG lan ZHAO Jin-fa ZHANG xing-kai wang Ying LI Tai-sheng ZHANG Wei ZHOU Yan National Citrus Engineering and Technology Research Center Citrus Research InstituteSouthwest UniversityChongqing 400712P.R.China Horticulture Research Institute Guangxi Academy of Agricultural SciencesNanning 530000P.R.China Plant Protection Station of Sichuan Agriculture and Rural Bureau Chengdu 610041P.R.China

In 2009, an emerging citrus viral disease caused by Citrus chlorotic dwarf-associated virus(CCDaV) was discovered in Yunnan Province of China. However, the occurrence and spread of CCDaV in other citrus-growing provinces in China is unknown to date. To better understand the distribution and molecular diversity of CCDaV in China, a total of 1 772 citrus samples were collected from 11 major citrus-growing provinces and were tested for CCDaV by PCR. Among these, 134 citrus samples from Guangxi, Yunnan and Guangdong were tested positive for CCDaV, demonstrating that the occurrence and spread of CCDaV are increasing in China. The complete genome sequences of 17 CCDaV isolates from different provinces and hosts were sequenced. Comparisons of the whole-genome sequences of the 17 CCDaV isolates as well as the 15 isolates available in GenBank revealed that the sequence identity was about 99–100%, showing that the CCDaV isolates were highly conserved. Phylogenetic studies showed that the 32 CCDaV isolates belonged to four different groups based on geographical origins and host species, and that CCDaV isolates from China and Turkey were clustered into different groups. The results provide important information for clarifying the distribution and genetic diversity of CCDaV in China.

关键词： Citrus chlorotic dwarf-associated virus detection sequence alignments phylogenetic tree analysis

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β-Arrestin-2 inhibits preference for alcohol in mice and suppresses Akt signaling in the dorsal striatum

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Neuroscience Bulletin 2013年第5期29卷 531-540页

作者： Haohong Li Yezheng Tao Li Ma xing Liu lan Ma The State Key Laboratory of Medical Neurobiology and the Pharmacology Research Center Shanghai Medical Collegeand the Institute of Brain Science Fudan University

In this study,we investigated the role ofβ-arrestin-2in alcohol preference using the two-bottle choice and conditioned place preference procedures in wild-type（WT）andβ-arrestin-2 knockout（KO）*** and righting reflex tests were performed to test alcohol *** possible molecular signals regulated byβ-arrestin-2 were analyzed by Western *** found thatβ-arrestin-2 KO mice showed a marked increase in voluntary alcohol consumption without significant differences in preference for saccharin or aversion to *** animals also exhibited higher conditioned place preference scores for alcohol than WT ***,KO mice showed reduced sensitivity to alcohol and increased blood alcohol ***,after the free consumption of alcohol,the activities of protein kinase B and glycogen synthase kinase 3β（GSK3β）increased in the dorsal striatum of WT mice,but not in KO mice,which showed high basal activity of Akt in the dorsal *** results suggest thatβ-arrestin-2 negatively regulates alcohol preference and reward,likely through regulating the activation of signaling pathways including Akt/GSK3βin the dorsal striatum.

关键词： β-arrestin alcohol preference Akt

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Effect of heat treatment on microstructure and mechanical properties of Ti-containing low alloy martensitic wear-resistant steel

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China Foundry 2023年第4期20卷 329-338页

作者： Kai lan wang Ding Yi-tao Yang School of Materials Science and Engineering Shanghai UniversityShanghai 200444China

Effects of quenching temperature and cooling conditions(water cooling and 10%NaCl cooling)on microstructure and mechanical properties of a 0.2%Ti low alloy martensitic wear-resistant steel used for die casting ejector plate were *** results show that lath martensite can be obtained after austenitizing in the range of 860-980℃and then water *** an increase in austenitizing temperature,the precipitate content gradually *** precipitates are mainly composed of TiC and Ti4C2S2,and their total content is between 1.15wt.%and 1.64wt.%.The precipitate phase concentration by water-cooling is higher than that by10%NaCl cooling due to the lower cooling rate of water *** the austeniting temperature increases,the hardness and tensile strength of both water cooled and 10%NaCl cooled steels firstly increase and then *** experimental steel exhibits the best comprehensive mechanical properties after being austenitized at 900℃,cooled by 10%NaCl,and then tempered at 200℃.Its hardness,ultimate tensile strength,and wear rate reach551.4 HBW,1,438.2 MPa,and 0.48×10^(-2)mg·m^(-1),respectively.

关键词： low alloy wear-resistant steel quenching temperature cooling condition precipitate retained austenite wear resistance

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Simultaneous denoising and resolution enhancement of seismic data based on elastic convolution dictionary learning

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Petroleum Science 2023年第4期20卷 2127-2140页

作者： Nan-Ying lan Fan-Chang Zhang Kai-Heng Sang xing-Yao Yin School of Geosciences China University of Petroleum(East China)QingdaoShandong266580China

Enhancing seismic resolution is a key component in seismic data processing, which plays a valuable role in raising the prospecting accuracy of oil reservoirs. However, in noisy situations, existing resolution enhancement methods are difficult to yield satisfactory processing outcomes for reservoir characterization. To solve this problem, we develop a new approach for simultaneous denoising and resolution enhancement of seismic data based on convolution dictionary learning. First, an elastic convolution dictionary learning algorithm is presented to efficiently learn a convolution dictionary with stronger representation capability from the noisy data to be processed. Specifically, the algorithm introduces the elastic L1/2 norm as a sparsity constraint and employs a steepest gradient descent strategy to efficiently solve the frequency-domain linear system with substantial computational cost in a half-quadratic splitting framework. Then, based on the learned convolution dictionary, a weighted convolutional sparse representation paradigm is designed to encode the noisy data to acquire an optimal sparse approximation of the effective signal. Subsequently, a high-resolution dictionary with a broadband spectrum is constructed by the proposed parameter scaling strategy and matched filtering technique on the basis of atomic spectrum modeling. Finally, the optimal sparse approximation of the effective signal and the constructed high-resolution dictionary are used for data reconstruction to obtain the seismic signal with high resolution and high signal-to-noise ratio. Synthetic and field dataset examples are executed to check the effectiveness and reliability of the developed method. The results indicate that this method has a more competitive performance in seismic applications compared with the conventional deconvolution and spectral whitening methods.

关键词： Simultaneous denoising and resolution enhancement Elastic convolution dictionary learning Weighted convolutional sparse representation Matched filtering

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Abrasive wear behavior of cast iron coatings plasma-sprayed at different mild steel substrate temperatures

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International Journal of Minerals,Metallurgy and Materials 2012年第8期19卷 733-738页

作者： Ya-zhe xing Qiu-lan Wei Chao-ping Jiang Jian-min Hao School of Materials Science and Engineering Chang'an University Xi'an 710064 China Department of Automotive Engineering Shaanxi College of Communication Technology Xi'an 710018 China

Three kinds of cast iron coatings were prepared by atmospheric plasma spraying. During the spraying, the mild steel substrate temperature was controlled to be averagely 50, 180, and 240℃, respectively. Abrasive wear tests were conducted on the coatings under a dry friction condition. It is ibund that the abrasive wear resistance is enhanced with the substrate temperature increasing. SEM observations show that the wear losses of the coatings during the wear tests mainly result from the spalling of the splats. Furthermore, the improved wear resis- tance of the coatings mainly owes to the formation of oxides and the enhancement in the mechanical properties with the substrate temperature increasing.

关键词： cast iron coatings plasma spraying wear bonding

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Comparison between linear and non-linear forms of pseudo-first-order and pseudo-second-order adsorption kinetic models for the removal of methylene blue by activated carbon

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Frontiers of Environmental Science & Engineering 2009年第3期3卷 320-324页

作者： Junxiong LIN lan wang College of Materials and Textiles Zhejiang Sci-Tech UniversityHangzhou 310018China

The best-fit equations of linear and non-linear forms of the two widely used kinetic models,namely pseudo-first-order and pseudo-second-order equations,were compared in this *** experimental kinetics of methylene blue adsorption on activated carbon was used for this *** the correlation coefficient(R2)and the normalized standard deviationΔq(%)were employed as error analysis methods to determine the best-fitting *** results show that the non-linear forms of pseudo-first-order and pseudo-second-order models were more suitable than the linear forms for fitting the experimental *** experimental kinetics may have been distorted by linearization of the linear kinetic equations,and thus,the non-linear forms of kinetic equations should be primarily used to obtain the adsorption *** addition,theΔq(%)method for error analysis may be better to determine the best-fitting model in this case.

关键词： adsorption pseudo-first order pseudo-second order kinetic model linear method non-linear method

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Poisoning the pika： must protection of grasslands be at the expense of biodiversity？

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Science China(Life Sciences) 2017年第5期60卷 545-547页

作者： lan Wu Hao wang Center for Nature and Society School of Life Sciences Peking University Beijing 100871 China

The plateau pika（Ochotona curzoniae）plays a keystone role in the grassland ecosystem on the Qinghai-Tibetan Plateau（QTP）（Smith and Foggin,1999;Lai and Smith,2003）,but in spite of its ecological importance it has... 详细信息

关键词：国家级自然保护区高原鼠兔生物多样性中毒草地生态系统草原青藏高原噪声比

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