oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 85 )

2018 ( 650 )

2017 ( 628 )

2016 ( 557 )

Custom range...

Search Results: 1 - 10 of 36853 matches for " ZHAO Qitao "
All listed articles are free for downloading (OA Articles)
Page 1 /36853
Display every page Item
Silencing of CHD5 Gene by Promoter Methylation in Leukemia
Rui Zhao, Fanyi Meng, Nisha Wang, Wenli Ma, Qitao Yan
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0085172
Abstract: Chromodomain helicase DNA binding protein 5 (CHD5) was previously proposed to function as a potent tumor suppressor by acting as a master regulator of a tumor-suppressive network. CHD5 is down-regulated in several cancers, including leukemia and is responsible for tumor generation and progression. However, the mechanism of CHD5 down-regulation in leukemia is largely unknown. In this study, quantitative reverse-transcriptase polymerase chain reaction and western blotting analyses revealed that CHD5 was down-regulated in human leukemia cell lines and samples. Luciferase reporter assays showed that most of the baseline regulatory activity was localized from 500 to 200 bp upstream of the transcription start site. Bisulfite DNA sequencing of the identified regulatory element revealed that the CHD5 promoter was hypermethylated in human leukemia cells and samples. Thus, CHD5 expression was inversely correlated with promoter DNA methylation in these samples. Treatment with DNA methyltransferase inhibitor 5-aza-2′-deoxycytidine (DAC) activates CHD5 expression in human leukemia cell lines. In vitro luciferase reporter assays demonstrated that methylation of the CHD5 promoter repressed its promoter activity. Furthermore, a chromatin immunoprecipitation assay combined with qualitative PCR identified activating protein 2 (AP2) as a potential transcription factor involved in CHD5 expression and indicated that treatment with DAC increases the recruitment of AP2 to the CHD5 promoter. In vitro transcription-factor activity studies showed that AP2 over-expression was able to activate CHD5 promoter activity. Our findings indicate that repression of CHD5 gene expression in human leukemia is mediated in part by DNA methylation of its promoter.
Generation of an external guide sequence library for a reverse genetic screen in Caenorhabditis elegans
Qitao Yan, Rui Zhao, Wenlin Zheng, Changxin Yin, Bao Zhang, Wenli Ma
BMC Biotechnology , 2009, DOI: 10.1186/1472-6750-9-47
Abstract: To examine whether EGS technology can be used to down-regulate gene expression in Caenorhabditis elegans (C. elegans), we generated EGS-Ngfp-lacZ and EGS-Mtgfp that are targeted against Ngfp-lacZ and Mtgfp mRNA, respectively. These EGSs were introduced, both separately and together, into the C. elegans strain PD4251, which contains Ngfp-lacZ and Mtgfp. Consequently, the expression levels of Ngfp-lacZ and Mtgfp were affected by EGS-Ngfp-lacZ and EGS-Mtgfp, respectively. We further generated an EGS library that contains a randomized antisense domain of tRNA-derived EGS ("3/4 EGS"). Examination of the composition of the EGS library showed that there was no obvious bias in the cloning of certain EGSs. A subset of EGSs was randomly chosen for screening in the C. elegans strain N2. About 6% of these EGSs induced abnormal phenotypes such as P0 slow postembryonic growth, P0 larval arrest, P0 larval lethality and P0 sterility. Of these, EGS-35 and EGS-83 caused the greatest phenotype changes, and their target mRNAs were identified as ZK858.7 mRNA and Lin-13 mRNA, respectively.EGS technology can be used to down-regulate gene expression in C. elegans. The EGS library is a research tool for reverse genetic screening in C. elegans. These observations are potentially of great importance to further our understanding and use of C. elegans genomics.RNase P catalyzes the maturation of 5'-termini of all tRNAs by a single endonucleolytic cleavage of their precursors[1]. This enzyme is found in cells from all three domains of life: the Bacteria, Eukaryote and Archaea [2-5]. One of the unique features of RNase P is its ability to recognize the structures, rather than the sequences, of tRNAs; this allows the enzyme to cleave other substrates with similar structure to the tRNA precursor. Accordingly, any complex of two RNA molecules that resembles a similar tRNA molecule can be recognized and cleaved by RNase P [6-8]. One of the two RNA molecules that resemble the complex is termed the ext
Crystallization properties of Sn--doped Ge--Sb--Te phase--change films
Sn掺杂Ge-Sb-Te相变薄膜的晶化特性

GU Sipeng,HOU Lisong,ZHAO Qitao,
顾四朋
,侯立松,赵启涛

材料研究学报 , 2004,
Abstract: Sn-doped Ge_2Sb_2Te_5 thin films were prepared by RF-sputtering.The effect of Sn- content on their crystallization properties was studied by XRD and DSC.The XRD spectra of the films in the as-deposited and heat-treated states showed that the films changed from amorphous to crystalline states due to heat-treatment and Sn-Te phase appeared.Using DSC data of the amorphous film materials,the activation energies were calculated by measuring the peak crystallization temperatures at different heating rates.It was found that the Ge-Sb-Te-Sn samples have higher activation energy of crystallization than that of the Ge_2Sb_2Te_5 sample.It is concluded from these results that Sn-doping can increase the crystallization rate of the Ge_2Sb_2Te_5 phase-change material,and thereby increase the erasing speed of the material for rewritable optical storage.
Study on Tourism Size of Provinces and Primary Cities in China
中国省际及主要旅游城市旅游规模

ZHU Hong,WU Qitao,
朱竑
,吴旗韬

地理学报 , 2005,
Abstract: Tourism has made great progress in China since the implementation of reform and opening-up policy, and the quantity of foreign and domestic tourists has a great increase not only in every province but also in cities. Based on the theory of primate city distribution and rank-size distribution which have been frequently used in urban geography since the 1920s, this paper uses the date of major cities and provinces to explain tourism size distribution on the scale of province and single city in China. Considering the possible error in recording the number of the domestic tourists, this paper selects the number of foreign tourists as the criterion of tourism size. On provincial scale, tourism size distribution follows primate city distribution, Beijing and Guangdong province are the primate province (city) in turn since 1990, the primate quotiety is between 1 to 1.6. What is more, according to the balance of the size and rank change, the tourism size growth mode of the province in China can be classified as equalization mode, accelerate growth mode, decelerate growth mode whereas through regression, tourism size turns out to follow the rank-size distribution on single city scale, the tourism size and its rank accords with the Pareto distribution well. Besides, this paper also discusses the impacts of the facts, such as economic condition, city function, tourism resource and boundary port on tourism size distribution, aiming at offering a new method for research of the tourism size and assisting the formulation of tourism policies at national and regional levels.
Bis[1-hydroxyethylidenediphosphonato(1 )](1,10-phenanthroline)nickel(II) monohydrate
Xiangdong Zhang,Chunhua Ge,Xiaoyan Zhang,Qitao Liu
Acta Crystallographica Section E , 2008, DOI: 10.1107/s1600536807065129
Abstract: In the mononuclear title compound, [Ni(C2H6O7P2)2(C12H8N2)]·H2O, the NiII atom (site symmetry 2) is bonded to two phosphate-based O,O′-bidentate chelate ligands and one N,N′-bidentate 1,10-phenanthroline ligand, resulting in a slightly distorted cis-NiN2O4 octahedral geometry. In the crystal structure, pairs of complexes are linked by double hydrogen bonds, forming a one-dimensional chain-like structure. Aromatic π–π stacking interactions [centroid–centroid separation = 3.768 (2) ] and further hydrogen bonds generate a two-dimensional structure. The water O atom also lies on a crystallographic twofold axis.
Analysis of Performance Effect Factors of Three-Stage Electro-Hydraulic Servo Valve
Xiaochu Liu,Qitao Huang,Dacheng Cong,Junwei Han
Journal of Computers , 2009, DOI: 10.4304/jcp.4.12.1216-1222
Abstract: A new modeling software, AMEsim is put forward in this paper to develop a nonlinear model for a higher performance three stage electro-hydraulic servo valve. The simulation results and experimental results on existing valve are consistent, which proves that the developed model is right. The analysis of the model shows that pilot valve bandwidth mainly affects the bandwidth of three-stage electro-hydraulic servo valve and is responsible for overshoot. The analysis also indicates that pilot valve resolution affects the resolution of three-stage electrohydraulic servo valve and pilot valve rated flow affects the bandwidth and overshoot. The result further reveal that the position transducer affects the bandwidth and overshoot, servo controller affects the bandwidth and stability, the spool diameter and mass affect the bandwidth and hydraulic natural frequency, flow force on spool affects the bandwidth, overlap distance of restriction edge affects the dead zone size of mid-position and resolution of midposition, coulomb friction force between spool and sleeve affects the resolution and radial clearance affects leakage flow and resolution. The analytical results are very useful because the methods can be applied to other similar systems.
Comparison of Salt Tolerance in Brassicas and Some Related Species  [PDF]
Jianjie Su, Shu Wu, Zhijie Xu, Si Qiu, Tingting Luo, Yimin Yang, Qitao Chen, Yuying Xia, Song Zou, Bang-Lian Huang, Bangquan Huang
American Journal of Plant Sciences (AJPS) , 2013, DOI: 10.4236/ajps.2013.410234
Abstract:

In this paper the salt tolerance in Brassicas and some related species was compared. When seedlings germinated on sand cultures with liquid MS medium were considered, the relative germination rate, root length, shoot length and fresh seedling weight were significantly correlated with each other (P < 0.01), and only the relative shoot lengths were significantly different among the tested genotypes (P < 0.05); When both seedlings germinated on MS and MS plus 0.4% NaCl were considered, only the relative shoot length of seedlings germinated on MS was significantly different from that germinated on MS + 0.4% NaCl (P < 0.05), and also only the relative shoot lengths were significantly different among the tested genotypes (P < 0.01). Raphanus sativa cv. Changfeng, B. juncea cv. JC and Brassica napus cv. ZS 10 showed low salt tolerance in terms of relative germination rate, root length, shoot length and fresh seedling weight; B. oleracea cv. JF-1, Sinapis alba cv. HN-2 showed high salt tolerance in terms of relative germination rate, root length, shoot length

Introducing antisense waxy gene into rice seeds reduces grain amylose contents using a safe transgenic technique
Jianyue Li,Wanxia Mao,Lijun Yang,Genyu Zhou,Jia Liu,Qitao Yan,Dong Mi
Chinese Science Bulletin , 2005, DOI: 10.1360/982004-378
Abstract: An agrobacterium tumefaciensmediated co-transformation method was established and successfully used to transfer an antisense waxy gene into rice. The binary vector pl3W4 contains an antisense waxy gene, a hygromycin resistance gene (hpt) and a report gene (gus). The other binary vector pl3W8 contains only an antisense waxy gene in the T-DNA region. Two separate strains of A. tumefaciens, containing pl3W4 and pl3W8 mixed at a ratio of 1: 9, were used to transform a high-yield rice strain Chao 2–10. A total of 34 transgenic plants were obtained. PCR analysis showed that 15 of them were co-transformed. After GUS staining, the T1 seeds with GUS positive were eliminated. The GUS negative T1 seeds were germinated, and the seedlings were analyzed for the existence of antisense waxy gene. The transgenic T1 plants with only antisense waxy gene further were confirmed through Southern blot analysis. The T2 seeds collected from marker-free T1 plants were used for amylose content analysis. The results showed that the amylose content in marker-free transgenic seeds reduced by up to 28.61% over the wild type rice. This marker-free transgenic rice with low amylose contents obtained in this project could be used to screen soft grain, and could also be used as a new rice resource for eating quality improvement.
Introducing antisense waxy gene into rice seeds reduces grain amylose contents using a safe transgenic technique
Jianyue Li,Wanxia Mao,Lijun Yang,Genyu Zhou,Jia Liu,Qitao Yan,Dong Mi,
LIJianyue
,MAOWanxia,YANGLijun,ZHOUGenyu,LIUJia,YANQitao,MIDong

科学通报(英文版) , 2005,
Abstract: An agrobacterium tumefaciensmediated co-transformation method was established and successfully used to transfer an antisense waxy gene into rice. The binary vector pl3W4 contains an antisense waxy gene, a hygromycin resistance gene (hpt) and a report gene (gus). The other binary vector pl3W8 contains only an antisense waxy gene in the T-DNA region. Two separate strains of A. tumefaciens, containing pl3W4 and pl3W8 mixed at a ratio of 1: 9, were used to transform a high-yield rice strain Chao 2–10. A total of 34 transgenic plants were obtained. PCR analysis showed that 15 of them were co-transformed. After GUS staining, the T1 seeds with GUS positive were eliminated. The GUS negative T1 seeds were germinated, and the seedlings were analyzed for the existence of antisense waxy gene. The transgenic T1 plants with only antisense waxy gene further were confirmed through Southern blot analysis. The T2 seeds collected from marker-free T1 plants were used for amylose content analysis. The results showed that the amylose content in marker-free transgenic seeds reduced by up to 28.61% over the wild type rice. This marker-free transgenic rice with low amylose contents obtained in this project could be used to screen soft grain, and could also be used as a new rice resource for eating quality improvement.
A Framework of Research and Practice: Relationship between Work Engagement, Affective Commitment, and Turnover Intentions  [PDF]
Liyu Zhao, Jingchao Zhao
Open Journal of Social Sciences (JSS) , 2017, DOI: 10.4236/jss.2017.510019
Abstract:
There is a growing research interest in the topic of work engagement over the past years. In reference to Schauefeli, Salanova, Gonzalez-Roma & Bakker (2002) [1], work engagement is described as “a positive, fulfilling work-related state of mind that is characterized by vigor, dedication and absorption”. As compare to the researches based on the relationship between work engagement and organizational commitment and job performance, the existing researches on the relationship between work engagement and turnover intentions are far fewer. We theoretically discussed the relationship among work engagement, affective commitment and turnover intentions. Research results show that work engagement is negatively related to turnover intentions whereby affective commitment plays a regulating role. Affective commitment moderates the relationship between work engagement and turnover intentions whereby employees’ affective commitment is stronger and employees are more willing to invest effort in their work; hence, employees’ turnover intentions are reduced.
Page 1 /36853
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.