OALib Journal期刊

ISSN: 2333-9721




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匹配条件: “ Qianqian Zhao” ,找到相关结果约34995条。
Effects of Ce4+ on Membrane Integrity of Rice in Seedling Hydroponic Cultures  [PDF]
Qiuman Xu, Qianqian Zhao, Chaoyu Zhao, Hong Chen
Agricultural Sciences (AS) , 2014, DOI: 10.4236/as.2014.59083

Rare earth elements have been extensively used as micro-fertilizers for crops in China. To understand the potential benefits or damages of Ce4+ on rice, the effects of Ce4+ on viability and membrane integrity of rice were investigated under hydroponic cultures. It has been found that the cell viability, electrical conductivity, pH changes, and concentration of malonyl dialdehyde did not change obviously when the content of Ce4+ was 0.5 mg/L, but varied markedly when the contents of Ce4+ were raised to 10 mg/L or more, indicating that the Ce4+ at higher concentrations severely affected the cell membrane permeability.

PCA-based bootstrap confidence interval tests for gene-disease association involving multiple SNPs
Qianqian Peng, Jinghua Zhao, Fuzhong Xue
BMC Genetics , 2010, DOI: 10.1186/1471-2156-11-6
Abstract: PCA-based bootstrap confidence interval test (PCA-BCIT), which directly uses the PC scores to assess gene-disease association, was developed and evaluated for three ways of extracting PCs, i.e., cases only(CAES), controls only(COES) and cases and controls combined(CES). Extraction of PCs with COES is preferred to that with CAES and CES. Performance of the test was examined via simulations as well as analyses on data of rheumatoid arthritis and heroin addiction, which maintains nominal level under null hypothesis and showed comparable performance with permutation test.PCA-BCIT is a valid and powerful method for assessing gene-disease association involving multiple SNPs.Genetic association studies now customarily involve multiple SNPs in candidate genes or genomic regions and have a significant role in identifying and characterizing disease-predisposing variant(s). A critical challenge in their statistical analysis is how to make optimal use of all available information. Population-based case-control studies have been very popular[1] and typically involve contingency table tests of SNP-disease association[2]. Notably, the genotype-wise Armitage trend test does not require HWE and has equivalent power to its allele-wise counterpart under HWE[3,4]. A thorny issue with individual tests of SNPs for linkage disequilibrium (LD) in such setting is multiple testing, however, methods for multiple testing adjustment assuming independence such as Bonferroni's[5,6] is knowingly conservative[7]. It is therefore necessary to seek alternative approaches which can utilize multiple SNPs simultaneously. The genotype-wise Armitage trend test is appealing since it is equivalent to the score test from logistic regression[8] of case-control status on dosage of disease-predisposing alleles of SNP. However, testing for the effects of multiple SNPs simultaneously via logistic regression is no cure for difficulty with multicollinearity and curse of dimensionality[9]. Haplotype-based methods ha
Vibration, Oscillation, and Escape of the Fiber-Optic Signal under Two-Frequency Perturbations
Jiuli Yin,Qianqian Xing,Liuwei Zhao
ISRN Mathematical Physics , 2014, DOI: 10.1155/2014/165250
Abstract: Chaos occurs easily in the nonlinear Schr?dinger equation with external perturbations owing to the absence of damping. For the process of information transmission, the perturbation will cause distortion. If we add a suitable controller, it is easy to discover that chaos still appears in the process of propagation of fiber-optic signal when the strength of controller is weak. With the strength of controller increasing, the propagation of fiber-optic signal will arrive at the stable state. As the strength exceeds a certain degree, the propagation of fiber-optic signal system would tend toward the unstable state. Moreover, we consider the parameters’ sensitivity to be controlled. The result demonstrates that the nonlinear term parameter and the two quite different frequencies have less effect on the propagation of fiber-optic signal. Meanwhile, the phenomena of vibration, oscillation, and escape occur in some regions. 1. Introduction The cubic quintic nonlinear Schr?dinger (NLS) equation is extensively used in various fields, especially for the process of the fiber-optic signal propagation [1]. Here represents the nondimensional distance along the fiber-optic signal, represents time in a dimensionless form, and and are real valued constants. The dependent variable function is a complex valued function that represents the signal wave profile. In a general way, (1) is a nonlinear partial differential equation, which is completely integrable on the infinite line or periodic boundary conditions in one dimension. As a matter of fact, the propagation of fiber-optic signal must be perturbed with external environment. Extensive systems with external perturbations have been widely investigated by using analytic methods and numerical simulations. A mass of bifurcation sets, the routes to chaos, and Lyapunov exponents are given in [2–4]. More attention has been paid to the interaction of external perturbations. The analysis of complex dynamics in three-well forcing or other systems with two external forcings are shown in [5–7]. Although these researches have played a certain role in chaos control, there are rarely researches on the fiber-optic signal models with two-frequency perturbations. However, two-frequency perturbations can model the fiber-optic signal under complex external conditions better. Hence, we consider the fiber-optic signal system (1) under two-frequency perturbations where are the amplitudes of the perturbations and are the frequencies; is the velocity of a certain signal. The research purposes of this paper are the two following vital points.
地质学报 , 2015,
Abstract: TheresearchonPaleozoictectonicsandendogenicmetallogenyintheTianshan-AltayregionofCentralAsiaisanimportantandsignificantproject.TheAltayregion,asacollisionzoneoftheEarlyPaleozoic(500?397Ma),andtheTianshanregion,asacollisionzoneoftheearlyperiodintheLatePaleozoic(LateDevonian-EarlyCarboniferous,385?323Ma),arealltheresultofnearlyN-Strendingshorteningandcollision(accordingtorecentmagneticorientation).IntheLateDevonian-EarlyCarboniferousperiod(385?323Ma),regionalNWtrendingfaultsdisplayedfeaturesofdextralstrike-slipmotionintheAltayandJunggarregions.IntheTianshanregion,nearlyEW-trendingregionalfaultsaremotionsofthethrusts.However,intheLateCarboniferous-EarlyPermianperiod(323?260Ma),influencedbythelong-distanceeffectinducedfromtheUralcollisionzone,thoseareassufferedweakereastwardcompression,theexistingNWtrendingfaultsconvertedintosinistralstrike-slipintheAltayandJunggarregions,andtheexistingnearlyE-Wtrendingfaultstransferredintodextralstrike-slipfaultsintheTianshanregion.TheRocksofthoseregionsintheLateCarboniferous-EarlyPermianperiod(323?260Ma)weremoderatelyrupturedtoacertaintension-shear,andthusformedanumberofworldfamousgiantendogenicmetaloredepositsintheTianshan-Altayregion.AstotheCentralAsiancontinent,themostpowerfulcollisionperiodmaynotcoincidewiththemostfavorableendogenicmetallogenicperiod.Itshouldbetreatedto“theorogenicmetallogenyhypothesis”withcautioninthatregion.
Fixed Point Results for Weakly C-Contraction Mapping in Modular Metric Spaces  [PDF]
Jinwei Zhao, Qianqian Zhao, Bo Jin, Linan Zhong
Open Access Library Journal (OALib Journal) , 2018, DOI: 10.4236/oalib.1104061
In this paper, we introduce the concept of weakly C-contraction mapping in modular metric spaces. And we established some fixed point results in w-complete spaces. Our results encompass various generalizations of Banach contraction.
Effects of fatty acid activation on photosynthetic production of fatty acid-based biofuels in Synechocystis sp. PCC6803
Qianqian Gao, Weihua Wang, Hui Zhao, Xuefeng Lu
Biotechnology for Biofuels , 2012, DOI: 10.1186/1754-6834-5-17
Abstract: Synechocystis sp. PCC6803 mutant strains containing either overexpression or deletion of the slr1609 gene, which encodes an acyl-ACP synthetase (AAS), have been constructed. The complete segregation and deletion in all mutant strains was confirmed by PCR analysis. Blocking fatty acid activation by deleting slr1609 gene in wild-type Synechocystis sp. PCC6803 led to a doubling of the amount of free fatty acids and a decrease of alkane production by up to 90 percent. Overexpression of slr1609 gene in the wild-type Synechocystis sp. PCC6803 had no effect on the production of either free fatty acids or alkanes. Overexpression or deletion of slr1609 gene in the Synechocystis sp. PCC6803 mutant strain with the capability of making fatty alcohols by genetically introducing fatty acyl-CoA reductase respectively enhanced or reduced fatty alcohol production by 60 percent.Fatty acid activation functionalized by the slr1609 gene is metabolically crucial for biosynthesis of fatty acid derivatives in Synechocystis sp. PCC6803. It is necessary but not sufficient for efficient production of alkanes. Fatty alcohol production can be significantly improved by the overexpression of slr1609 gene.Biofuel production from renewable sources is considered as a feasible solution to the energy and environmental problems we are facing. It is very important to explore and develop advanced biofuels alongside traditional biofuels such as bioethanol and biodiesel to ensure sufficient supply of renewable energy at a time when demand for energy is set to increase over the coming decades. Advanced biofuels possess higher energy density, hydrophobic properties and compatibility with existing liquid fuel infrastructure including fuel engines, refinery equipment and transportation/distribution pipelines, whilst serving as better alternatives to fuels produced from fossil fuels [1].In terms of fuel properties the best replacement of petroleum fuels is "Petroleum Fuels". This means ideal biofuels produced f
An analysis of farmers' perception of the new cooperative medical system in Liaoning Province, China
Xilong Pan, Ying Zhang, Li Xu, Ju Huang, Qianqian Zhao
BMC Health Services Research , 2009, DOI: 10.1186/1472-6963-9-230
Abstract: The data for this study were collected from a survey involving twenty counties in Liaoning Province. Interviews and focus groups were conducted between 10th January and 20th August 2008. A total of 2,780 people aged 18-72 were randomly selected and interviewed. Data were evaluated by nonparametric tests and ordinal regression models.71.6% of the study subjects were satisfied with the NRCMS. Single factor analysis showed that attitudes towards the NRCMS were influenced by gender, age, marital status, and self-rated health status. In the ordinal regression analysis, gender, age, and self-rated health status affect satisfaction (P < 0.05).We found that a considerable proportion of farmers were satisfied with the NRCMS. Gender, age, and self-rated health status had significant effects on farmers' attitudes towards the NRCMS. The Chinese Central Government attempted to adopt active measures in the future to continuously improve the NRCMS, including initiating educational programs, building new medical facilities and increasing financial investment.The New Cooperative Medical System (NCMS) is a main component of the Chinese new rural medical insurance system. The development of Chinese rural medical insurance system has gone through three stages:The forming period of the Cooperative Medical System (CMS) (1958-1980s): Before 1958, economic development was slow in rural China. No medical insurance system existed. In 1958, the National People's Congress of China (NPC) decided that the rural cooperative community, which was based on traditional geographic village, should be built as the most fundamental government agency in rural areas,. The CMS was established in the rural cooperative community to provide basic medical insurance to the community memembers, and in return each member made fixed contribution to CMS every year. Thus the communitymembers were insured by the CMS in case they needed medical care. This system played a significant role in promoting healthcare in rura
Lats2 Modulates Adipocyte Proliferation and Differentiation via Hippo Signaling
Yang An, Qianqian Kang, Yaofeng Zhao, Xiaoxiang Hu, Ning Li
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0072042
Abstract: First identified in Drosophila and highly conserved in mammals, the Hippo pathway controls organ size. Lats2 is one of the core kinases of the Hippo pathway and plays major roles in cell proliferation by interacting with the downstream transcriptional cofactors YAP and TAZ. Although the function of the Hippo pathway and Lats2 is relatively well understood in several tissues and organs, less is known about the function of Lats2 and Hippo signaling in adipose development. Here, we show that Lats2 is an important modulator of adipocyte proliferation and differentiation via Hippo signaling. Upon activation, Lats2 phosphorylates YAP and TAZ, leading to their retention in the cytoplasm, preventing them from activating the transcription factor TEAD in the nucleus. Because TAZ remains in the cytoplasm, PPARγ regains its transcriptional activity. Furthermore, cytoplasmic TAZ acts as an inhibitor of Wnt signaling by suppressing DVL2, thereby preventing β-catenin from entering the nucleus to stimulate TCF/LEF transcriptional activity. The above effects contribute to the phenotype of repressed proliferation and accelerated differentiation in adipocytes. Thus, Lats2 regulates the balance between proliferation and differentiation during adipose development. Interestingly, our study provides evidence that Lats2 not only negatively modulates cell proliferation but also positively regulates cell differentiation.
Compressing Information of Target Tracking in Wireless Sensor Networks  [PDF]
Jianzhong Li, Qianqian Ren
Wireless Sensor Network (WSN) , 2011, DOI: 10.4236/wsn.2011.32008
Abstract: Target tracking is a well studied topic in wireless sensor networks. It is a procedure that nodes in the network collaborate in detecting targets and transmitting their information to the base-station continuously, which leads to data implosion and redundancy. To reduce traffic load of the network, a data compressing based target tracking protocol is proposed in this work. It first incorporates a clustering based data gather method to group sensor nodes into clusters. Then a novel threshold technique with bounded error is proposed to exploit the spatial correlation of sensed data and compress the data in the same cluster. Finally, the compact data presentations are transmitted to the base-station for targets localization. We evaluate our approach with a comprehensive set of simulations. It can be concluded that the proposed method yields excellent performance in energy savings and tracking quality.
The Complete Mitochondrial Genome of Ctenoptilum vasava (Lepidoptera: Hesperiidae: Pyrginae) and Its Phylogenetic Implication
Jiasheng Hao,Qianqian Sun,Huabin Zhao,Xiaoyan Sun,Yonghua Gai,Qun Yang
Comparative and Functional Genomics , 2012, DOI: 10.1155/2012/328049
Abstract: We here report the first complete mitochondrial (mt) genome of a skipper, Ctenoptilum vasava Moore, 1865 (Lepidoptera: Hesperiidae: Pyrginae). The mt genome of the skipper is a circular molecule of 15,468 bp, containing 2 ribosomal RNA genes, 24 putative transfer RNA (tRNA), genes including an extra copy of trnS (AGN) and a tRNA-like insertion trnL (UUR), 13 protein-coding genes and an AT-rich region. All protein-coding genes (PCGs) are initiated by ATN codons and terminated by the typical stop codon TAA or TAG, except for COII which ends with a single T. The intergenic spacer sequence between trnS (AGN) and ND1 genes also contains the ATACTAA motif. The AT-rich region of 429 bp is comprised of nonrepetitive sequences, including the motif ATAGA followed by an 19 bp poly-T stretch, a microsatellite-like (AT)3 (TA)9 element next to the ATTTA motif, an 11 bp poly-A adjacent to tRNAs. Phylogenetic analyses (ML and BI methods) showed that Papilionoidea is not a natural group, and Hesperioidea is placed within the Papilionoidea as a sister to ((Pieridae

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