A HYBRID METHOD FOR NCP WITH P_0 FUNCTIONS

Qian Zhou,Yi-Gui Ou 한국전산응용수학회 2011 Journal of applied mathematics & informatics Vol.29 No.3

This paper presents a new hybrid method for solving nonlinear complementarity problems with P_0-functions. It can be regarded as a combination of smoothing trust region method with ODE-based method and line search technique. A feature of the proposed method is that at each iteration, a linear system is only solved once to obtain a trial step, thus avoiding solving a trust region subproblem. Another is that when a trial step is not accepted, the method does not resolve the linear system but generates an iterative point whose step-length is defined by a line search. Under some conditions, the method is proven to be globally and superlinearly convergent. Preliminary numerical results indicate that the proposed method is promising.

A HYBRID METHOD FOR NCP WITH $P_0$ FUNCTIONS

Zhou, Qian,Ou, Yi-Gui The Korean Society for Computational and Applied M 2011 Journal of applied mathematics & informatics Vol.29 No.3

This paper presents a new hybrid method for solving nonlinear complementarity problems with $P_0$-functions. It can be regarded as a combination of smoothing trust region method with ODE-based method and line search technique. A feature of the proposed method is that at each iteration, a linear system is only solved once to obtain a trial step, thus avoiding solving a trust region subproblem. Another is that when a trial step is not accepted, the method does not resolve the linear system but generates an iterative point whose step-length is defined by a line search. Under some conditions, the method is proven to be globally and superlinearly convergent. Preliminary numerical results indicate that the proposed method is promising.

Spatial interpolation of daily precipitation in China: 1951??2005

Chen, D.,Ou, T.,Gong, L.,Xu, C. Y.,Li, W.,Ho, C. H.,Qian, W. Springer Science + Business Media 2010 ADVANCES IN ATMOSPHERIC SCIENCES Vol.27 No.6

ST6Gal-I Predicts Postoperative Clinical Outcome for Patients with Localized Clear-cell Renal Cell Carcinoma

Liu, Hai-Ou,Wu, Qian,Liu, Wei-Si,Liu, Yi-Dong,Fu, Qiang,Zhang, Wei-Juan,Xu, Le,Xu, Jie-Jie Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.23

Hyperactivated ${\alpha}2$-6-sialylation on N-glycans due to overexpression of the Golgi enzyme ${\beta}$-galactoside: ${\alpha}2$-6-sialyltransferase (ST6Gal-I) often correlates with cancer progression, metastasis, and poor prognosis. This study was aimed to determine the association between ST6Gal-I expression and the risk of recurrence and survival of patients with localized clear-cell renal cell carcinoma (ccRCC) following surgery. We retrospectively enrolled 391 patients (265 in training cohort and 126 in validation cohort) with localized ccRCC underwent nephrectomy at a single center. Tissue microarrays were constructed for immunostaining of ST6Gal-I. Prognostic value and clinical outcomes were evaluated. High ST6Gal-I expression was associated with Fuhrman grade (p<0.001 and p=0.016, respectively) and the University of California Los-Angeles Integrated Staging System (UISS) score (p=0.004 and p=0.017, respectively) in both cohorts. Patients with high ST6Gal-I expression had significantly worse overall survival (OS) (p<0.001 and p<0.001, respectively) and recurrence free survival (RFS) (p<0.001 and p=0.002, respectively) than those with low expression in both cohorts. On multivariate analysis, ST6Gal-I expression remained associated with OS and RFS even after adjusting for the UISS score. Stratified analysis suggested that the association is more pronounced among patients with low and intermediate-risk disease defined by the UISS score. High ST6Gal-I expression is a potential independent adverse predictor of survival and recurrence in ccRCC patients, and the prognostic value is most prominent in those with low and intermediate-risk disease defined by the UISS score.

Cloning and Identification of a Novel C18-Δ9 Polyunsaturated Fatty Acid Specific Elongase Gene from DHA-producing Isochrysis galbana H29

Ming Li,Xiuyuan Ou,Xiangdong Yang,Dongquan Guo,Xueyan Qian,Laijun Xing,Mingchun Li 한국생물공학회 2012 Biotechnology and Bioprocess Engineering Vol.17 No.1

Isochrysis galbana, a marine prymnesiophyte microalga, is able to produce a high level of long chain polyunsaturated fatty acids such as docosahexaenoic acid (DHA, C22:6n-3). In this article, a novel gene (IgASE2)that encoded a C18-Δ9 polyunsaturase fatty acids specific (C18-Δ9-PUFAs-specific) elongase was isolated and characterized from DHA-rich microalga, I. galbana H29. A full-length cDNA of 1653 bp was cloned by rapidamplification of cDNA ends (RACE) PCR techniques. The IgASE2 contained a 786 bp ORF encoding a protein of 261amino acids that shared 87% identity with the reported Δ9-elongase IgASE1, a 44 bp 5' untranslated region and an 823 bp 3' untranslated region. The function of IgASE2 was demonstrated by its heterologous expression in Saccharomyces cerevisiae. In S. cerevisiae, IgASE2 elongated linoleic acid (LA, C18:2n-6), α-linolenic (ALA, C18:3n-3) to eicosadienoic acid (EDA, C20:2n-6) and eicosatrienoic acid (ETrA, C20:3n-3). The conversion ratios of LA to EDA and ALA to ETrA were 60.47 and 58.36%, respectively. However, IgASE2 could not catalyze the elongation reactions of oleic acid (OA, C18:1n-9) and other fatty acids. These results confirmed that IgASE2 had C18-Δ9-PUFAs-specific elongase activity. Isochrysis galbana, a marine prymnesiophyte microalga, is able to produce a high level of long chain polyunsaturated fatty acids such as docosahexaenoic acid (DHA, C22:6n-3). In this article, a novel gene (IgASE2)that encoded a C18-Δ9 polyunsaturase fatty acids specific (C18-Δ9-PUFAs-specific) elongase was isolated and characterized from DHA-rich microalga, I. galbana H29. A full-length cDNA of 1653 bp was cloned by rapidamplification of cDNA ends (RACE) PCR techniques. The IgASE2 contained a 786 bp ORF encoding a protein of 261amino acids that shared 87% identity with the reported Δ9-elongase IgASE1, a 44 bp 5' untranslated region and an 823 bp 3' untranslated region. The function of IgASE2 was demonstrated by its heterologous expression in Saccharomyces cerevisiae. In S. cerevisiae, IgASE2 elongated linoleic acid (LA, C18:2n-6), α-linolenic (ALA, C18:3n-3) to eicosadienoic acid (EDA, C20:2n-6) and eicosatrienoic acid (ETrA, C20:3n-3). The conversion ratios of LA to EDA and ALA to ETrA were 60.47 and 58.36%, respectively. However, IgASE2 could not catalyze the elongation reactions of oleic acid (OA, C18:1n-9) and other fatty acids. These results confirmed that IgASE2 had C18-Δ9-PUFAs-specific elongase activity.

Enzymatic Manufacture of Deoxythymidine-5`-Triphosphate with Permeable Intact Cells of E. coli Coexpressing Thymidylate Kinase and Acetate Kinase

( Jiao Zhang ),( Yahui Qian ),( Qingbao Ding ),( Ling Ou ) 한국미생물 · 생명공학회 2015 Journal of microbiology and biotechnology Vol.25 No.12

A one-pot process of enzymatic synthesis of deoxythymidine-5`-triphosphate (5`-dTTP) employing whole cells of recombinant Escherichia coli coexpressing thymidylate kinase (TMKase) and acetate kinase (ACKase) was developed. Genes tmk and ack from E. coli were cloned and inserted into pET28a(+), and then transduced into E. coli BL21 (DE3) to form recombinant strain pTA in which TMKase and ACKase were simultaneously overexpressed. It was found that the relative residual specific activities of TMKase and ACKase, in pTA pretreated with 20 mM ethylene diamine tetraacetic acid (EDTA) at 25℃ for 30 min, were 94% and 96%, respectively. The yield of 5`-dTTP reached above 94% from 5 mM deoxythymidine 5`-monophosphate (5`-dTMP) and 15 mM acetyl phosphate catalyzed with intact cells of pTA pretreated with EDTA. The process was so effective that only 0.125 mM adenosine-5`-triphosphate was sufficient to deliver the phosphate group from acetyl phosphate to dTMP and dTDP.

Isolation and Identification of Lipopeptide Antibiotics from Paenibacillus elgii B69 with Inhibitory Activity Against Methicillin-Resistant Staphylococcus aureus

Rui Ding,Chao-Dong Qian,Yi Teng,Ou Li,Zha-Jun Zhan,Yu-Hua Zhao,Xue-Chang Wu 한국미생물학회 2011 The journal of microbiology Vol.49 No.6

Two lipopeptide antibiotics, pelgipeptins C and D, were isolated from Paenibacillus elgii B69 strain. The molecular masses of the two compounds were both determined to be 1,086 Da. Mass-spectrometry, amino acid analysis and NMR spectroscopy indicated that pelgipeptin C was the same compound as BMY-28160, while pelgipeptin D was identified as a new antibiotic of the polypeptin family. These two peptides were active against all the tested microorganisms, including antibiotic-resistant pathogenic bacterial strains such as methicillin-resistant Staphylococcus aureus (MRSA). Time-kill assays demonstrated that pelgipeptin D exhibited rapid and effective bactericidal action against MRSA at 4×MIC. Based on acute toxicity test, the intraperitoneal LD50 value of pelgipeptin D was slightly higher than that of the structurally related antimicrobial agent polymyxin B. Pelgipeptins are highly potent antibacterial and antifungal agents, particularly against MRSA, and warrant further investigation as possible therapeutic agents for bacteria infections resistant to currently available antibiotics.

One-pot Process of 2'-Deoxyguanylic Acid Catalyzed by a Multi-enzyme System

Yanyu Li,Qingbao Ding,Ling Ou,Yahui Qian,Jiao Zhang 한국생물공학회 2015 Biotechnology and Bioprocess Engineering Vol.20 No.1

2'-Deoxyguanylic acid (deoxyguanosine-5'-monophosphate, dGMP) is a substance required by livingcells that is used extensively in reagents, fine chemicalsand other industrial fields. Traditionally, dGMP is separatedfrom DNA degradation products, which is low-yieldingand time-consuming. Herein, we investigated a novel, onepotmulti-enzymatic cascade reaction to produce dGMP. This reaction involved purine nucleoside phosphorylase(PNPase) and acetate kinase (ACKase) from Escherichiacoli, N-deoxyribosytransferase II (NDT-II) from Lactobacillusdelbrueckii and deoxyguanosine kinase (dGKase) fromBacillus subtilis. During the reaction, the initial guanosinesubstrate was cleaved into guanine and ribose-1-phosphateby PNPase. Then, deoxyguanosine (dGR) was subsequentlyproduced from a reaction between guanine and thymidinecatalysed by NDT-II. Finally, the intermediate dGR wasphosphorylated to dGMP by dGKase and a cytidinetriphosphate (CTP) regeneration system that utilised acetylphosphate via ACKase. A very small amount of CTP wasadded because CTP regeneration was efficient to transfer aphosphate group from acetyl phosphate to dGR. After 12 hof incubation, a maximal dGMP yield of up to 76% wasobtained based on the addition of 5 mM guanosine and 5mM thymidine.

Maternal betaine supplementation ameliorates fatty liver disease in offspring mice by inhibiting hepatic NLRP3 inflammasome activation

Li Lun,Sun Liuqiao,Liang Xiaoping,Ou Qian,Tan Xuying,Li Fangyuan,Lai Zhiwei,Ding Chenghe,Chen Hangjun,Yu Xinxue,Wu Qiongmei,Wei Jun,Wu Feng,Wang Lijun 한국영양학회 2023 Nutrition Research and Practice Vol.17 No.6

BACKGROUND/OBJECTIVES: Previous research has shown maternal betaine supplementation alleviates fetal-derived hepatic steatosis. Therefore, this study examined the anti-inflammatory effect of maternal betaine intake in offspring mice and its mechanism. MATERIALS/METHODS: Female C57BL/6J mice and their offspring were randomly divided into 3 groups according to the treatment received during gestation and lactation: control diet (CD), fatty liver disease (FLD), and fatty liver disease + 1% betaine (FLD-BET). The FLD group was given a high-fat diet and streptozotocin (HFD + STZ), and the FLD-BET group was treated with HFD + STZ + 1% betaine. After weaning, the offspring mice were given a normal diet for 5 weeks and then dissected to measure the relevant indexes. RESULTS: Compared to the CD group, the offspring mice in the FLD group revealed obvious hepatic steatosis and increased serum levels of alanine aminotransferase, interleukin (IL)-6, and tumor necrosis factor (TNF)-α; maternal betaine supplementation reversed these changes. The hepatic mRNA expression levels of IL-6, IL-18, and Caspase-1 were significantly higher in the FLD group than in the CD group. Maternal betaine supplementation reduced the expression of IL-1β, IL-6, IL-18, and apoptosis-associated speck-like protein containing C-terminal caspase recruitment domain (ASC). Maternal betaine supplementation also reversed the increasing protein expressions of nitric oxide dioxygenase-like receptor family pyrin domain containing 3 (NLRP3), ASC, Caspase-1, IL-1β, and IL-18 in offspring mice exposed to HFD + STZ. Maternal betaine supplementation decreased the homocysteine (Hcy) and s-adenosine homocysteine (SAH) levels significantly in the livers. Furthermore, the hepatic Hcy concentrations showed significant inverse relationships with the mRNA expression of TNF-α, NLRP3, ASC, and IL-18. The hepatic SAH concentration was inversely associated with the IL-1β mRNA expression. CONCLUSIONS: The lipotropic and anti-inflammatory effect of maternal betaine supplementation may be associated with the inhibition of NLRP3 inflammasome in the livers of the offspring mice.

Isolation and Identification of Newly Isolated Antagonistic Streptomyces sp. Strain AP19-2 Producing Chromomycins

Wu, Xue-Chang,Chen, Wei-Feng,Qian, Chao-Dong,Li, Ou,Li, Ping,Wen, Yan-Ping The Microbiological Society of Korea 2007 The journal of microbiology Vol.45 No.6

A new antagonistic strain of actinomycete, designated AP19-2, was isolated from the feces of giant pandas inhabiting the Foping National Nature Reserve in China. Cultural characteristic studies strongly suggested that this strain is a member of the genus Streptomyces. The nucleotide sequence of the 16S rRNA gene of strain AP19-2 evidenced profound similarity (97-99 %) with other Streptomyces strains. Two pure active molecules were isolated from a fermentation broth of Streptomyces sp. strain AP19-2 via extraction, concentration, silica gel G column chromatography, and HPLC. The chemical structures of the two related compounds (referred to as chromomycin $A_2$ and chromomycin $A_3$) were established on the basis of their Infrared spectra (IR), High Resolution Electrospray Ionization Mass Spectrometry (HR-ESI-MS), and Nuclear Magnetic Resonance (NMR) data, and by comparison with published data.