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Moderate Deviations for Parameter Estimation in the Fractional Ornstein–Uhlenbeck Processes with Periodic Mean

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Acta Mathematica Sinica,English Series 2024年第5期40卷 1308-1324页

作者： Hui JIANG Shi Min LI wei gang wang School of Mathematics Nanjing University of Aeronautics and AstronauticsNanjing 210016P.R.China The People's Bank of China Operations Ofice of Nanjing Branch Nanjing 210016P.R.China School of Statistics and Mathematics Zhejiang Gongshang UniversityHangzhou 310018P.R.China

In this paper,we study the asymptotic properties for the drift parameter estimators in the fractional Ornstein-Uhlenbeck process with periodic mean function and long range *** Cremér-type moderate deviations,as well ... 详细信息

关键词： Cramér-type moderate deviation fractional Ornstein-Uhlenbeck process parameter estimation multiple Wiener-Ito integrals

Gastric motor effects of ghrelin and growth hormone releasing peptide 6 in diabetic mice with gastroparesis

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World Journal of Gastroenterology 2008年第9期14卷 1419-1424页

作者： Wen-Cai Qiu Zhi-gang wang wei-gang wang Jun Yan Qi Zheng The Affiliated Sixth Hospital of Medical School Shanghai Jiaotong University Shanghai 200233 China

AIM:To investigate the potential therapeutic significance of ghrelin and growth hormone releasing peptide 6 (GHRP-6) in diabetic mice with gastric motility disorders. METHODS: A diabetic mouse model was established by intraperitoneal (ip) injection of alloxan. Diabetic mice were injected ip with ghrelin or GHRP-6 (20-200 μg/kg), and the effects on gastric emptying were measured after intragastric application of phenol red. The effect of atropine, NG-nitro-L-arginine methyl ester hydrochloride (L-NAME) or D-Lys3-GHRP-6 (a growth hormone secretagogue receptor (GHS-R) antagonist) on the gastroprokinetic effect of ghrelin or GHRP-6 (100 μg/kg) was also investigated. The effects of ghrelin or GHRP-6 (0.01-10 μmol/L) on spontaneous or carbachol-induced contractile amplitude were also investigated in vitro, in gastric fundic circular strips taken from diabetic mice. The presence of growth hormone secretagogue receptor 1a transcripts in the fundic strips of diabetic mice was detected by reverse transcriptase polymerase chain reaction (RT-PCR). RESULTS: We established a diabetic mouse model with delayed gastric emptying. Ghrelin and GHRP-6 accelerated gastric emptying in diabetic mice with gastroparesis. In the presence of atropine or L-NAME, which delayed gastric emptying, ghrelin and GHRP-6 (100 μg/kg) failed to accelerate gastric emptying. D-Lys3-GHRP-6 also delayed gastric emptying induced by the GHS-R agonist. Ghrelin and GHRP-6 increased the carbachol-induced contractile amplitude in gastric fundicstrips taken from diabetic mice. RT-PCR confirmed the presence of GHS-R mRNA in the strip preparations. CONCLUSION: Ghrelin and GHRP-6 increase gastric emptying in diabetic mice with gastroparesis, perhaps by activating peripheral cholinergic pathways in the enteric nervous system.

关键词： Gastric emptying Ghrelin Growth hormone releasing peptide 6 Growth hormone secretagogue receptor Diabetic mice

Harmonic Moments of Branching Processes in Random Environments

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Acta Mathematica Sinica,English Series 2009年第7期25卷 1087-1096页

作者： wei gang wang Ping LV Di He HU School of Statistics and Mathematics Zhejiang Gongshang University Hangzhou 310018 P. R. China Department of Science Hangzhou Normal University Hangzhou 310036 P. R. China School of Mathematics and Statistics Wuhan University Wuhan 430072 P. R. China

We consider harmonic moments of branching processes in general random environments. For a sequence of square integrable random variables, we give some conditions such that there is a positive constant c that every var... 详细信息

关键词： branching processes in random environments harmonic moments

Dimension Results for Space-anisotropic Gaussian Random Fields

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Acta Mathematica Sinica,English Series 2019年第3期35卷 391-406页

作者： Wen Qing NI Zhen Long CHEN wei gang wang School of Statistics and Mathematics Zhejiang Gongshang University School of Science Jimei University

Let X = {X(t) ∈ R^d, t ∈ R^N} be a centered space-anisotropic Gaussian random field whose components satisfy some mild conditions. By introducing a new anisotropic metric in R^d, we obtain the Hausdorff and packing dimension in the new metric for the image of X. Moreover, the Hausdorff dimension in the new metric for the image of X has a uniform version.

关键词： Hausdorff dimension packing dimension gaussian random field uniform dimension

The Limit Theorems for Random Walk with State Space R in a Space-time Random Environment

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Acta Mathematica Sinica,English Series 2008年第4期24卷 655-662页

作者： wei gang wang Zhen Long GAO Di He HU School of Statistics and Mathematics Zhejiang Gongshang University Hangzhou 310018 P. R. China School of Mathematics and Statistics Wuhan University Wuhan 430072 P. R. China School of Mathematics Anyang Normal University Anyang 455000 P. R. China

We consider a discrete time random environment. We state that when the random walk on real number space in a environment is i.i.d., under the law, the law of large numbers, iterated law and CLT of the process are correct space-time random marginal annealed Using a martingale approach, we also state an a.s. invariance principle for random walks in general random environment whose hypothesis requires a subdiffusive bound on the variance of the quenched mean, under an ergodic invariant measure for the environment chain.

关键词： space-time random environment the law of large numbers CLT iterated law invariance principle

Group Analysis, Fractional Explicit Solutions and Conservation Laws of Time Fractional Generalized Burgers Equation

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Communications in Theoretical Physics 2018年第1期69卷 5-8页

作者： gang-wei wang A. H. Kara School of Mathematics and Statistics Hebei University of Economics and Business Shijiazhuang 050061 China School of Mathematics University of the Witwatersrand Private Bag 3 Wits 2050 Johannesburg South Afric

The generalized fractional Burgers equation is studied in this paper. Using the classical Lie symmetry method, all of the vector fields and symmetry reduction of the equation with nonlinearity are constructed. In particular, an exact solution ＆ provided by using the ansatz method. In addition, other types of exact solution are obtained via the invariant subspace method. Finally, conservation laws for this equation are derived.

关键词： time fractional generalized Burgers equation Lie symmetry method explicit solutions conservation laws

Prokinetic effects of a ghrelin receptor agonist GHRP-6 in diabetic mice

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World Journal of Gastroenterology 2008年第30期14卷 4795-4799页

作者： Qi Zheng Wen-Cai Qiu Jun Yan wei-gang wang Song Yu Zhi-gang wang Kai-Xing Ai Department of General Surgery The Affiliated Sixth Hospital of Medical School Shanghai Jiaotong University Shanghai 200233 China

AIM： To investigate the effects of a ghrelin receptor agonist GHRP-6 on delayed gastrointestinal transit in alloxan-induced diabetic mice. METHODS： A diabetic mouse model was established by intraperitoneal injection with alloxan. Mice were randomized into two main groups： normal mice and diabetic mice treated with GHRP-6 at doses of 0, 20, 50, 100 and 200 μg/kg ip. Gastric emptying （GE）, intestinal transit （IT）, and colonic transit （CT） were studied in mice after they had a phenol red meal following injection of GHRP-6. Based on the most effective GHRP-6 dosage, atropine was given at 1 mg/kg for 15 rain before the GHRP-6 injection for each measurement. The mice in each group were sacrificed 20 min later and the percentages of GE, IT, and CT were calculated. RESULTS： Percentages of GE, IT, and CT were significantly decreased in diabetic mice as compared to control mice. In the diabetic mice, GHRP-6 improved both GE and IT, but not CT. The most effective dose of GHRP-6 was 200 μg/kg and atropine blocked the prokinetic effects of GHRP-6 on GE and IT. CONCLUSION： GHRP-6 accelerates delayed GE and IT, but has no effect on CT in diabetic mice. GHRP-6 may exert its prokinetic effects via the cholinergic pathway in the enteric nervous system, and therefore, has therapeutic potential for diabetic patients with delayed upper gastrointestinal transit.

关键词： GHRP-6 Diabetes mellitus Gastric emptying Intestinal transit Colonic transit

Ghrelin improves delayed gastrointestinal transit in alloxan-induced diabetic mice

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World Journal of Gastroenterology 2008年第16期14卷 2572-2577页

作者： Wen-Cai Qiu Zhi-gang wang Ran Lv wei-gang wang Xiao-Dong Han Jun Yan Yu wang Qi Zheng Kai-Xing Ai Department of General Surgery The Aflihated Sixth Hospital of Medical School Shanghai Jiaotong University Shanghai 200233 China Department of Anesthesiology Sir Run Run Shaw Hospital School of Medicine Zhejiang University Hangzhou 310016 Zhejiang Province China

AIM: To investigate the effects of ghrelin on delayed gastrointestinal transit in alloxan-induced diabetic mice. METHODS: A diabetic mouse model was established by intraperitoneal injection with alloxan. Mice were randomized into two main groups: normal mice group and diabetic mice group treated with ghrelin at doses of 0, 20, 50, 100 and 200 μg/kg ip. Gastric emptying (GE), intestinal transit (IT), and colonic transit (CT) were studied in mice after they had a phenol red meal following injection of ghrelin. Based on the most effective ghrelin dosage, atropine was given at 1 mg/kg 15 min before the ghrelin injection for each measurement. The mice in each group were sacrificed 20 min later and their stomachs, intestines, and colons were harvested immediately. The amount of phenol red was measured. Percentages of GE, IT, and CT were calculated. RESULTS: Percentages of GE, IT, and CT were significantly decreased in diabetic mice as compared to control mice (22.9 ± 1.4 vs 28.1 ± 1.3, 33.5 ± 1.2 vs 43.2 ± 1.9, 29.5 ± 1.9 vs 36.3 ± 1.6, P < 0.05). In the diabetic mice, ghrelin improved both GE and IT, but not CT. The most effective dose of ghrelin was 100 μg/kg and atropine blocked the prokinetic effects of ghrelin on GE and ***: Ghrelin accelerates delayed GE and IT but has no effect on CT in diabetic mice. Ghrelin may exert its prokinetic effects via the cholinergic pathway in the enteric nervous system, and therefore has therapeutic potential for diabetic patients with delayed upper gastrointestinal transit.

关键词： Ghrelin Diabetes mellitus Gastric emptying Intestinal transit Colonic transit

Phosphine oxide directing-group-enabled atroposelective C-H bond acyloxylation via an eight-membered palladacycle intermediate

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Chinese Chemical Letters 2023年第5期34卷 277-280页

作者： Peng-Bo Bai Ming-Ying Wu Xin-Xin Yang gang-wei wang Shang-Dong Yang State Key Laboratory of Applied Organic Chemistry Lanzhou UniversityLanzhou 730000China State Key Laboratory for Oxo Synthesis and Selective Oxidation Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China

Herein,we report the first atroposelective C(sp^(2))-H bond acyloxylation enabled by a phosphine oxide directing ***,this transformation is shown to proceed through an eight-membered palladacycle intermediate,as opposed to the kinetically and thermodynamically favored five-membered palladacycle ***,L-pGlu-OH,a cheap and abundant chiral amino acid derivative,was identified as the best chiral ligand to promote this atroposelective remote C-H functionalization reaction.

关键词： Palladiumcatalyst Axially chiral Acetylation Dibenzophosphorus oxide