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Search Results: 1 - 10 of 81041 matches for " Yingchun Liu "
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Perhydrobenzimidazole-2-thione
YingChun Liu,XiaoYu Li
Acta Crystallographica Section E , 2009, DOI: 10.1107/s1600536808043894
Abstract: The studied crystal of the title compound, C7H12N2S, is a racemic mixture of two isomers, viz. S,S and R,R. The two isomers share the same position on a mirror plane in the space group P21/m; thus all atoms except one are disordered between two positions in a 1:1 ratio. Intermolecular N—H...S hydrogen bonds link the molecules into chains propagating in the [010] direction.
Revealing signaling pathway deregulation by using gene expression signatures and regulatory motif analysis
Yingchun Liu, Markus Ringnér
Genome Biology , 2007, DOI: 10.1186/gb-2007-8-5-r77
Abstract: Genetic aberrations and variations in cellular processes are usually reflected in the expression levels of many genes. Hence, such alterations can potentially be characterized by their gene expression profiles. Gene expression profiling, in particular DNA microarray analysis, has been widely used in attempts to reveal the underlying mechanisms of many diseases, different developmental stages, cellular responses to different conditions, and many other biological phenomena (for example, [1-3]). Gene expression signatures consisting of tens to hundreds of genes have been associated with many important aspects of the systems studied. To help realize the full potential of gene expression studies, a variety of methods, such as GenMAPP [4], GoMiner [5], DAVID [6] and its desktop version EASE [7], Catmap [8], ArrayXPath [9], and Gene Set Enrichment Analysis (GSEA) [10], have been developed to relate gene expression profiles or signatures to a broad range of biological categories. Although some of these methods include signaling pathways in their categories, their focus has not been on regulatory mechanisms that control the observed gene expression changes.Signal transduction is at the core of many regulatory systems. Cellular functions such as growth, proliferation, differentiation, and apoptosis are regulated by signaling pathways. Appropriate regulation of such pathways is essential for the normal functioning of cells. Cells affected by disease often have one or several signaling pathways abnormally activated or inactivated. For example, cancer is a disease of deregulated cell proliferation and death [11]. To uncover mechanisms underlying cellular phenotypes, therefore, it is crucial to systematically analyze gene expression signatures in the context of signaling pathways. In signal transduction, ligands, usually from outside the cell, interact with receptors on the surface of the cell membrane or with nuclear receptors. These interactions trigger a cascade of biochemical
Multiclass discovery in array data
Yingchun Liu, Markus Ringnér
BMC Bioinformatics , 2004, DOI: 10.1186/1471-2105-5-70
Abstract: We describe the implementation of an unsupervised classification method for class discovery in microarray data. The method allows for discovery of more than two classes. We applied our method on two published microarray data sets: small round blue cell tumors and breast tumors. The method predicts relevant classes in the data sets with high success rates.We conclude that the proposed method is accurate and efficient in finding biologically relevant classes in microarray data. Additionally, the method is useful for quality control of microarray experiments. We have made the method available as a computer program.A common application in microarray data analysis is to identify genes that, based on their expression levels, discriminate between known classes of experiments. This identification is often achieved by using various statistical measures to, gene-by-gene, correlate the expression levels with the classes of interest. In this way a discriminatory weight is calculated for each gene. For example, Golub et al. used a signal-to-noise statistic to find genes with expression patterns that discriminate between samples obtained from patients with acute myeloid leukemia and patients with acute lymphoblastic leukemia [1]. Other examples include using a standard t-test to discriminate between breast tumors from carriers of BRCA1 mutations and carriers of BRCA2 mutations [2]. For an overview of applications see [3]. In most studies, the number of genes is much larger than the number of experiments. For such a large number of genes, it is crucial to estimate how many genes would correlate with the classes of interest by chance. Often, a P value corresponding to the probability of obtaining a given weight by chance is calculated for each weight. One can then investigate if there is an over-abundance of discriminatory genes for classes of interest as compared to randomly selected classes. Indeed, such an over-abundance has been found for many microarray-based classification ap
Effect of hormonal status and metabolic changes of restricted ewes during late pregnancy on their fetal growth and development
Feng Gao,XianZhi Hou,YingChun Liu
Science China Life Sciences , 2007, DOI: 10.1007/s11427-007-0098-x
Abstract: This study investigated the effects of hormonal status and metabolic changes of restricted ewes during late pregnancy on the ovine fetus growth and development. One hundred Mongolian ewes, synchronized for oestrus and mated, were divided into three groups and offered 0.175 MJME·kgw 0.75·d 1 (Restricted Group 1, RG1), 0.33 MJME·kgw 0.75·d 1 (Restricted Group 2, RG2) and ad libitum access to feed (Control Group, CG) during their late pregnancy respectively. The results suggested that with the supply of exogenous energy decreasing during late pregnancy, maternal body weight and net body weight loss in RG2 and RG1 were lower than those of CG (Ps0.01). The insulin and IGF-1 concentrations of ewes in RG2 and RG1 tended to be lower than those of CG (P>0.05), but the GH concentrations in RG2 and RG1 were enhanced and there was significant difference between RG1 and CG on d 120 of gestation (P<0.05). The glucose concentration of ewes in RG2 and RG1 was decreased throughout the feed restriction period, and the differences were observed between RG1 and CG on d 120 of gestation (P<0.05). In addition, the nonesterified fatty acid (NEFA) and total amino acid (TAA) concentrations of ewes in RG2 tended to increase, but there was no significant difference (P>0.05). However, the NEFA and FAA concentrations of ewes in RG1 were reduced from d 90 to d 120 of gestation, then enhanced from d 120 to d 140 of gestation. During the late pregnancy, with the supply of nutrition decreasing, the negatively physiological and biochemical maternal reactions to restriction became worse, which significantly reduced the average lamb birth weight and daily growth rate of fetus in RG2 (P<0.05) and RG1 (P<0.01).
Effect of hormonal status and metabolic changes of restricted ewes during late pregnancy on their fetal growth and development
GAO Feng,HOU XianZhi &,LIU YingChun,

中国科学C辑(英文版) , 2007,
Abstract: This study investigated the effects of hormonal status and metabolic changes of restricted ewes during late pregnancy on the ovine fetus growth and development. One hundred Mongolian ewes, synchronized for oestrus and mated, were divided into three groups and offered 0.175 MJME·kgw 0.75·d 1 (Restricted Group 1, RG1), 0.33 MJME·kgw 0.75·d 1 (Restricted Group 2, RG2) and ad libitum access to feed (Control Group, CG) during their late pregnancy respectively. The results suggested that with the supply of exogenous energy decreasing during late pregnancy, maternal body weight and net body weight loss in RG2 and RG1 were lower than those of CG (Ps0.01). The insulin and IGF-1 concentrations of ewes in RG2 and RG1 tended to be lower than those of CG (P>0.05), but the GH concentrations in RG2 and RG1 were enhanced and there was significant difference between RG1 and CG on d 120 of gestation (P<0.05). The glucose concentration of ewes in RG2 and RG1 was decreased throughout the feed restriction period, and the differences were observed between RG1 and CG on d 120 of gestation (P<0.05). In addition, the nonesterified fatty acid (NEFA) and total amino acid (TAA) concentrations of ewes in RG2 tended to increase, but there was no significant difference (P>0.05). However, the NEFA and FAA concentrations of ewes in RG1 were reduced from d 90 to d 120 of gestation, then enhanced from d 120 to d 140 of gestation. During the late pregnancy, with the supply of nutrition decreasing, the negatively physiological and biochemical maternal reactions to restriction became worse, which significantly reduced the average lamb birth weight and daily growth rate of fetus in RG2 (P<0.05) and RG1 (P<0.01). Supported by the National Natural Science Foundation ( NSFC) of China (Grant Nos. 30460095 and 30360074), Doctoral Fund of Ministry of Education of China (20060129008) and Scientific Research Foundation for Doctor of Inner Mongolia Agricultural University (BJ06-36)
Information & Communication Convergence for the Promotion of Electric Power Enterprise Informationization
Liu Siyuan,Zheng Xunzhao,Wang Yingchun
Lecture Notes in Engineering and Computer Science , 2009,
Abstract:
Study on the Multi-Component Quantitation of Cortex Moutan and Its Intestinal Absorption Characteristics  [PDF]
Mei Ge, Xihong Hou, Shimeng Li, Kunpeng Liu, Ziyi Han, Siyu Hao, Zhongliang Zeng, Yingchun Zhang
Pharmacology & Pharmacy (PP) , 2019, DOI: 10.4236/pp.2019.103013
Abstract:
Cortex Moutan (Paeonia suffruticosa Andr.) is a common traditional Chinese medicine and has been widely used in clinic for 2000 years in China. As sources for this crude drug are always mixed with other species, many cultivars on herbal market may lead to quality instability. Multi-component quantitative analysis is an efficient method to reflect chemical profiles of herb medicine and is always taken as the main method for quality evaluation. So, the aim of this work is to develop analytical method to quantify paeonol, paeoniflorin, gallic acid, oxypaeoniflorin, benzoylpaeoniflorin and paeonolide in Cortex Moutan (CM) to evaluate the chemical qualities of CM from different species or cultivars. Besides, we also study the intestinal absorption characteristics of paeonol and paeoniflorin for further pharmacological evaluation. In the present study, all of the standard markers were performed on an Ecosil C18 (250 mm × 4.6 mm, 5 μM, Lubex Co., Guangzhou, China) with linear gradient elution of 0.2% formic acid water and acetonitrile. The proposed method was applied to analyze 50 batches of samples with acceptable linearity (R2, 0.9995 - 0.9999), precisions (RSD, 0.47% - 2.08%), repeatability (RSD, 039% - 2.63%), stability (RSD, 0.52% -
AgBr-Coupled TiO2: A Visible Heterostructured Photocatalyst for Degrading Dye Pollutants
Jianjun Liu,Yingchun Yu,Zhixin Liu,Shengli Zuo,Baoshan Li
International Journal of Photoenergy , 2012, DOI: 10.1155/2012/254201
Abstract: A series of AgBr/TiO2 visible photocatalysts with heterojunction structure was synthesized using Ti(OC4H9)4, KBr, and AgNO3 as precursors. The phase composition, particle morphology and size, microstructures, and absorbance of these photocatalysts were characterized by X-ray diffraction, transmission electron microscope (TEM), high-resolution TEM, and UV-vis spectra. It was found that the coupled AgBr/TiO2 was an effective photocatalyst to degrade the methylene blue under visible light irradiation, compared with the other noncoupled photocatalysts of AgBr, AgBr/P25, and P25. The photocatalytic activities of AgBr/TiO2 increase first and then decrease with increasing the mass ratio of AgNO3/TiO2 and the photocatalyst with the mass ratio of 3.35 has the highest photocatalytic activity. The results showed that the coupled photocatalyst has the particle size of about 15 nm with homogeneous dispersion and has the strongest absorption in whole UV-vis light region (250~800 nm) originated from the synergetic effect of heterostructured AgBr/TiO2. The coupled AgBr/TiO2 photocatalyst can keep stable photocatalytic activity after five-circle runs.
Existence of Qiongnan suture zone on the north margin of South China Sea
Hailing Liu,Pin Yan,Yingchun Liu,Hui Deng
Chinese Science Bulletin , 2006, DOI: 10.1007/s11434-006-9107-x
Abstract: This paper aims to explore whether paleo-suture zone exists in the pre-Cenozoic basement of South China Sea (SCS). By taking advantage of integrated geophysical surveying data, including multi-channel reflection seismicity, oceanic bottom seismicity, gravity and magnetic data as well as paleomagnetism and drilling information, a comprehensive analysis on sedimentary stratigraphy, seismic stratigraphy, magmatic and metamorphic petrology, geochemistry, gravity study, magnetics, paleogeomagnetics as well as geotectonics was carried out, and the results clearly indicate that a pre-Cenozoic suture zone, i.e. “Qiongnan (south Hainan Island) suture zone”, does exist on the north margin of SCS. This suture zone starts in the west from the Jiusuo-Lingshui fault zone in the south of Hainan Island, extends eastward across the continental slope to the north of SCS, and links with Shoufeng fault in Taiwan. It is inferred that the Qiongnan suture zone was sutured approximately in Indosinian (Triassic) Epoch and is actually the vestige of “Qiongnan ocean basin”, the extension of the main paleo-Tethys ocean basin in SCS. The formation of Qiongnan suture zone marked the collision-accretion of the Qiongnan Block toward the Qiongzhong Block. The Qiongnan suture zone is linked to the west with the southward extension of the principal suture zone of the Paleo-Tethys at Bitu-Changning-Menglian-Bentong-Raub, across the southern segment of the Red River-East Vietnam-Wanna strike-slip fault zone, and connected to the east with the suture zone emplaced into the south margin of the Oki-Hida Pre-Jurassic terranes in southwest Japan, across the northern segment of the Manila trench fault zone in the northeast side of Taiwan Island. The discovery of this suture zone is believed to be potentially significant toward study of the pre-Cenozoic geotectonic pattern of SCS, the temporal and spatial distribution of the east paleo-Tethys structural domain in SCS and the relationship of recombination and superimposition between the east paleo-Tethys structural domain and the west Pacific structural domain, in addition to the oil/gas geological potentials in the pre-Cenozoic marine vestige-superimposed basin in the study area.
Laminar premixed methane/air flame extinction characteristics influenced by co-flow water mists
XuanYa Liu,ShouXiang Lu,YingChun Zhu,Yi Liu
Chinese Science Bulletin , 2008, DOI: 10.1007/s11434-008-0013-2
Abstract: Based on the tubular burner, the burning velocities, flame stretch and inhibition rules influenced by co-flow water mists were studied using a high-speed schlieren system. Moreover, the variation rules of the flame critical extinction in our burner equipment were also obtained by analyzing the process and mechanism of flame extinction and inhibition. It is shown that the flame stretch is related to the fuel concentration, co-flow fluxes and water mist diameters. For droplets with a larger diameter, the smaller the co-flow fluxes, the more obvious the flame stretch. When the water mist loading rate is rather smaller, for fuel-rich premixed flame with Le>1, the flame with larger burning rate tends to backfire more easily. Under the same water mist conditions, for fuel-lean premixed flame with Le<1, the smaller the gas concentration, the easier the flame is extinct.
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