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Dai C, Jiang M, Sun MJ. Letter: the effects of rifaximin in hepatic encephalopathy. Aliment Pharmacol Ther 2014; 40:857-8. [PMID: 25185736 DOI: 10.1111/apt.12889] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/08/2022]
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77
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Dai C, Wang Y, Quan Y, Chen Q, Cheng Y, Zhu C. Chiral sensing of Eu(III)-containing achiral polymer complex from chiral amino acids coordination induction. ACTA ACUST UNITED AC 2014. [DOI: 10.1002/pola.27356] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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78
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Dai C, Cai XH, Cai YP, Guo HC, Sun W, Tan Q, Huang GH. An integrated simulation and optimization approach for managing human health risks of atmospheric pollutants by coal-fired power plants. JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION (1995) 2014; 64:704-720. [PMID: 25039204 DOI: 10.1080/10962247.2014.886639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
UNLABELLED This research developed a simulation-aided nonlinear programming model (SNPM). This model incorporated the consideration of pollutant dispersion modeling, and the management of coal blending and the related human health risks within a general modeling framework In SNPM, the simulation effort (i.e., California puff [CALPUFF]) was used to forecast the fate of air pollutants for quantifying the health risk under various conditions, while the optimization studies were to identify the optimal coal blending strategies from a number of alternatives. To solve the model, a surrogate-based indirect search approach was proposed, where the support vector regression (SVR) was used to create a set of easy-to-use and rapid-response surrogates for identifying the function relationships between coal-blending operating conditions and health risks. Through replacing the CALPUFF and the corresponding hazard quotient equation with the surrogates, the computation efficiency could be improved. The developed SNPM was applied to minimize the human health risk associated with air pollutants discharged from Gaojing and Shijingshan power plants in the west of Beijing. Solution results indicated that it could be used for reducing the health risk of the public in the vicinity of the two power plants, identifying desired coal blending strategies for decision makers, and considering a proper balance between coal purchase cost and human health risk. IMPLICATIONS A simulation-aided nonlinear programming model (SNPM) is developed. It integrates the advantages of CALPUFF and nonlinear programming model. To solve the model, a surrogate-based indirect search approach based on the combination of support vector regression and genetic algorithm is proposed. SNPM is applied to reduce the health risk caused by air pollutants discharged from Gaojing and Shijingshan power plants in the west of Beijing. Solution results indicate that it is useful for generating coal blending schemes, reducing the health risk of the public, reflecting the trade-offbetween coal purchase cost and health risk.
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Lv S, Han M, Yi R, Kwon S, Dai C, Wang R. Anti-TNF-α therapy for patients with sepsis: a systematic meta-analysis. Int J Clin Pract 2014; 68:520-8. [PMID: 24548627 DOI: 10.1111/ijcp.12382] [Citation(s) in RCA: 100] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
OBJECTIVE In humans, the role of anti-tumour necrosis factor (TNF)-α therapy in severe sepsis and septic shock is debatable. The aim of this meta-analysis was to determine the efficacy of anti-TNF-α therapies against placebo in patients with severe sepsis or septic shock. METHODS A structured literature search was undertaken to identify randomised controlled trials (RCTs) conducted in patients with severe sepsis or septic shock receiving anti-TNF-α therapy or placebo. A meta-analysis on relative risk (OR) with a 95% confidence interval (95% CI) was performed. RESULTS Seventeen studies with a total of 8971 patients were included. When all forms of anti-TNF-α therapy were pooled together, there was a significant reduction of 28-day all-cause mortality with respect to placebo (OR = 0.91, 95% CI: 0.83-0.99; p = 0.04). Subgroup analysis showed that anti-TNF-α antibodies (monoclonal and polyclonal) reduced mortality (OR = 0.90, 95% CI: 0.81-0.99; p = 0.04). Monoclonal antibodies enhanced survival (OR = 0.91, 95% CI: 0.82-1.00; p = 0.05), while polyclonal antibodies or receptor blockers did not enhance survival (OR = 0.71, 95% CI: 0.39-1.28, p = 0.25; OR = 0.95, 95% CI: 0.78-1.17, p = 0.65). There was a trend towards better survival in patients with high levels of IL-6 (> 1000 pg/ml) and patients with shock if they were treated with anti-TNF-α therapy (OR = 0.85, 95% CI: 0.72-1.00; OR = 0.80, 95% CI: 0.62-1.04). Publication bias and statistical heterogeneity (I(2) < 50% and p > 0.1) were absent. Sensitivity analysis suggests that these results are highly stable. CONCLUSIONS This meta-analysis suggests that in patients with severe sepsis (before shock), immunotherapy with anti-TNF-α monoclonal antibodies reduces overall mortality. In patients with shock or high levels of IL-6 (> 1000 pg/ml), anti-TNF-α therapy may improve survival.
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Yoon S, Lee H, Fraiwan A, Dai C, Choi S. A Microsized Microbial Solar Cell: A demonstration of photosynthetic bacterial electrogenic capabilities. IEEE NANOTECHNOLOGY MAGAZINE 2014. [DOI: 10.1109/mnano.2014.2310073] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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81
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Zheng X, Liang Y, Kang A, Ma SJ, Xing L, Zhou YY, Dai C, Xie H, Xie L, Wang GJ, Hao HP. Peripheral immunomodulation with ginsenoside Rg1 ameliorates neuroinflammation-induced behavioral deficits in rats. Neuroscience 2013; 256:210-22. [PMID: 24161284 DOI: 10.1016/j.neuroscience.2013.10.023] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Revised: 10/09/2013] [Accepted: 10/11/2013] [Indexed: 01/13/2023]
Abstract
Neuroinflammatory disturbances have been closely associated with depression and many other neuropsychiatric diseases. Although targeting neuroinflammatory mediators with centrally acting drugs has shown certain promise, its translation is faced with several challenges especially drug delivery and safety concerns. Here, we report that neuroinflammation-induced behavioral abnormality could be effectively attenuated with immunomodulatory agents that need not to gain brain penetration. In a rat model with intracerebral lipopolysaccharide (LPS) challenge, we validated that ginsenoside Rg1 (Rg1), a well-established anti-inflammatory agent, was unable to produce a direct action in the brain. Interestingly, peripherally restricted Rg1 could effectively attenuate the weight loss, anorexic- and depressive-like behavior as well as neurochemical disturbances associated with central LPS challenge. Biochemical assay of neuroimmune mediators in the periphery revealed that Rg1 could mitigate the deregulation of the hypothalamic-pituitary-adrenal axis and selectively blunt the increase in circulating interleukin-6 levels. Furthermore, these peripheral regulatory effects were accompanied by dampened microglial activation, mitigated expression of pro-inflammatory mediators and neurotoxic species in the central compartment. Taken together, our work suggested that targeting the peripheral immune system may serve as a novel therapeutic approach to neuroinflammation-induced neuropsychiatric disorders. Moreover, our findings provided the rationale for employing peripherally active agents like Rg1 to combat mental disturbances.
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Wang J, Guan X, Guo F, Zhou J, Chang A, Sun B, Cai Y, Ma Z, Dai C, Li X, Wang B. miR-30e reciprocally regulates the differentiation of adipocytes and osteoblasts by directly targeting low-density lipoprotein receptor-related protein 6. Cell Death Dis 2013; 4:e845. [PMID: 24113179 PMCID: PMC3824666 DOI: 10.1038/cddis.2013.356] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Revised: 08/09/2013] [Accepted: 08/12/2013] [Indexed: 01/08/2023]
Abstract
Reciprocal relationship usually exists between osteoblastogenesis and adipogenesis, with factors stimulating one of these processes at the same time inhibiting the other. In the present study, miR-30e was found to be involved in the reciprocal regulation of osteoblast and adipocyte differentiation. Our data indicated that miR-30e was induced in primarily cultured mouse bone marrow stromal cell, mesenchymal cell line C3H10T1/2 and preadipocyte 3T3-L1 after adipogenic treatment. Conversely, it was reduced in mouse stromal line ST2 and preosteoblast MC3T3-E1 after osteogenic treatment. Enforced expression of miR-30e in 3T3-L1 significantly suppressed the growth of the cells and induced the preadipocytes to differentiate into mature adipocytes, along with increased expression of adipocyte-specific transcription factors peroxisome proliferator-activated receptor-γ (PPARγ), CCAAT/enhancer binding protein-α (C/EBPα) and C/EBPβ, and the marker gene aP2. In contrast, inhibition of the endogenous miR-30e enhanced the cell growth and repressed preadipocytes to differentiate. Conversely, supplementing miR-30e activity blocked, whereas knocking down miR-30e enforced the preosteoblast MC3T3-E1 to fully differentiate. Furthermore, miR-30e overexpression stimulated adipocyte formation and inhibited osteoblast differentiation from marrow stromal cells. Low-density lipoprotein receptor-related protein 6 (LRP6), one of the critical coreceptor for Wnts, was shown to be a direct target of miR-30e by using the luciferase assay. Knockdown of LRP6 in 3T3-L1 cells downregulated β-catenin/T-cell factor (TCF) transcriptional activity and dramatically potentiated the differentiation of the cells into mature adipocytes. Taken together, the present work suggests that the expression of miR-30e is indispensable for maintaining the balance of adipocytes and osteoblasts by targeting the canonical Wnt/β-catenin signaling.
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Wei G, Zhang S, Dai C, Quan Y, Cheng Y, Zhu C. A New Chiral Binaphthalene-Based Fluorescence Polymer Sensor for the Highly Enantioselective Recognition of Phenylalaninol. Chemistry 2013; 19:16066-71. [DOI: 10.1002/chem.201302726] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Indexed: 01/11/2023]
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84
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Dai C, Galloway LF. Sexual selection in a hermaphroditic plant through female reproductive success. J Evol Biol 2013; 26:2622-32. [DOI: 10.1111/jeb.12254] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Revised: 07/22/2013] [Accepted: 08/26/2013] [Indexed: 11/29/2022]
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85
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Dai C, Zheng CQ, Jiang M. Letter: serotonin transporter gene polymorphisms and the irritable bowel syndrome. Aliment Pharmacol Ther 2013; 37:657-8. [PMID: 23406411 DOI: 10.1111/apt.12222] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Accepted: 01/05/2013] [Indexed: 12/11/2022]
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86
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Lv Y, Huang GH, Guo L, Li YP, Dai C, Wang XW, Sun W. A scenario-based modeling approach for emergency evacuation management and risk analysis under multiple uncertainties. JOURNAL OF HAZARDOUS MATERIALS 2013; 246-247:234-244. [PMID: 23314394 DOI: 10.1016/j.jhazmat.2012.11.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2012] [Revised: 11/03/2012] [Accepted: 11/03/2012] [Indexed: 06/01/2023]
Abstract
Nuclear emergency evacuation is important to prevent radioactive harms by hazardous materials and to limit the accidents' consequences; however, uncertainties are involved in the components and processes of such a management system. In the study, an interval-parameter joint-probabilistic integer programming (IJIP) method is developed for emergency evacuation management under uncertainties. Optimization techniques of interval-parameter programming (IPP) and joint-probabilistic constrained (JPC) programming are incorporated into an integer linear programming framework, so that the approach can deal with uncertainties expressed as joint probability and interval values. The IJIP method can schedule the optimal routes to guarantee the maximum population evacuated away from the effected zone during a finite time. Furthermore, it can also facilitate post optimization analysis to enhance robustness in controlling system violation risk imposed on the joint-probabilistic constraints. The developed method has been applied to a case study of nuclear emergency management; meanwhile, a number of scenarios under different system conditions have been analyzed. It is indicated that the solutions are useful for evacuation management practices. The result of the IJIP method can not only help to raise the capability of disaster responses in a systematic manner, but also provide an insight into complex relationships among evacuation planning, resources utilizations, policy requirements and system risks.
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88
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Dai C, Wei X, Tai Y, Zhao F. The optimum design of power distribution for pressurized water reactor. ANN NUCL ENERGY 2012. [DOI: 10.1016/j.anucene.2012.07.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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89
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Nguyen JD, Reiss B, Dai C, Stephenson CRJ. Batch to flow deoxygenation using visible light photoredox catalysis. Chem Commun (Camb) 2012; 49:4352-4. [PMID: 23142826 DOI: 10.1039/c2cc37206a] [Citation(s) in RCA: 99] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Herein we report a one-pot deoxygenation protocol for primary and secondary alcohols developed via the combination of the Garegg-Samuelsson reaction, visible light-photoredox catalysis, and flow chemistry. This procedure is characterized by mild reaction conditions, easy-to-handle reactants and reagents, excellent functional group tolerance, and good yields.
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90
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Baker J, Brown K, Rajendiran E, Yip A, DeCoffe D, Dai C, Molcan E, Chittick SA, Ghosh S, Mahmoud S, Gibson DL. Medicinal lavender modulates the enteric microbiota to protect against Citrobacter rodentium-induced colitis. Am J Physiol Gastrointest Liver Physiol 2012; 303:G825-36. [PMID: 22821949 DOI: 10.1152/ajpgi.00327.2011] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Inflammatory bowel disease, inclusive of Crohn's disease and ulcerative colitis, consists of immunologically mediated disorders involving the microbiota in the gastrointestinal tract. Lavender oil is a traditional medicine used to relieve many gastrointestinal disorders. The goal of this study was to examine the therapeutic effects of the essential oil obtained from a novel lavender cultivar, Lavandula×intermedia cultivar Okanagan lavender (OLEO), in a mouse model of acute colitis caused by Citrobacter rodentium. In colitic mice, oral gavage with OLEO resulted in less severe disease, including decreased morbidity and mortality, reduced intestinal tissue damage, and decreased infiltration of neutrophils and macrophages, with reduced levels of TNF-α, IFN-γ, IL-22, macrophage inflammatory protein-2α, and inducible nitric oxide synthase expression. This was associated with increased levels of regulatory T cell populations compared with untreated colitic mice. Recently, we demonstrated that the composition of the enteric microbiota affects susceptibility to C. rodentium-induced colitis. Here, we found that oral administration of OLEO induced microbiota enriched with members of the phylum Firmicutes, including segmented filamentous bacteria, which are known to protect against the damaging effects of C. rodentium. Additionally, during infection, OLEO treatment promoted the maintenance of microbiota loads, with specific increases in Firmicutes bacteria and decreases in γ-Proteobacteria. We observed that Firmicutes bacteria were intimately associated with the apical region of the intestinal epithelial cells during infection, suggesting that their protective effect was through contact with the gut wall. Finally, we show that OLEO inhibited C. rodentium growth and adherence to Caco-2 cells, primarily through the activities of 1,8-cineole and borneol. These results indicate that while OLEO promoted Firmicutes populations, it also controlled pathogen load through antimicrobial activity. Overall, our results reveal that OLEO can protect against colitis through the microbial-immunity nexus and that a pharmacological agent, in this case OLEO, alters the normal enteric microbiota.
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91
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Baker J, Brown K, Rajendiran E, Yip A, DeCoffe D, Dai C, Molcan E, Chittick SA, Ghosh S, Mahmoud S, Gibson DL. Medicinal lavender modulates the enteric microbiota to protect against Citrobacter rodentium-induced colitis. Am J Physiol Gastrointest Liver Physiol 2012. [PMID: 22821949 DOI: 10.1152/ajpgi.00327] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Inflammatory bowel disease, inclusive of Crohn's disease and ulcerative colitis, consists of immunologically mediated disorders involving the microbiota in the gastrointestinal tract. Lavender oil is a traditional medicine used to relieve many gastrointestinal disorders. The goal of this study was to examine the therapeutic effects of the essential oil obtained from a novel lavender cultivar, Lavandula×intermedia cultivar Okanagan lavender (OLEO), in a mouse model of acute colitis caused by Citrobacter rodentium. In colitic mice, oral gavage with OLEO resulted in less severe disease, including decreased morbidity and mortality, reduced intestinal tissue damage, and decreased infiltration of neutrophils and macrophages, with reduced levels of TNF-α, IFN-γ, IL-22, macrophage inflammatory protein-2α, and inducible nitric oxide synthase expression. This was associated with increased levels of regulatory T cell populations compared with untreated colitic mice. Recently, we demonstrated that the composition of the enteric microbiota affects susceptibility to C. rodentium-induced colitis. Here, we found that oral administration of OLEO induced microbiota enriched with members of the phylum Firmicutes, including segmented filamentous bacteria, which are known to protect against the damaging effects of C. rodentium. Additionally, during infection, OLEO treatment promoted the maintenance of microbiota loads, with specific increases in Firmicutes bacteria and decreases in γ-Proteobacteria. We observed that Firmicutes bacteria were intimately associated with the apical region of the intestinal epithelial cells during infection, suggesting that their protective effect was through contact with the gut wall. Finally, we show that OLEO inhibited C. rodentium growth and adherence to Caco-2 cells, primarily through the activities of 1,8-cineole and borneol. These results indicate that while OLEO promoted Firmicutes populations, it also controlled pathogen load through antimicrobial activity. Overall, our results reveal that OLEO can protect against colitis through the microbial-immunity nexus and that a pharmacological agent, in this case OLEO, alters the normal enteric microbiota.
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92
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Dai C, Wei X, Tai Y, Zhao F. The optimum design of tight lattice reactor core with thin rod bundles. PROGRESS IN NUCLEAR ENERGY 2012. [DOI: 10.1016/j.pnucene.2012.03.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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93
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Dai C, Liang B, Stephenson CRJ. Expanding the chemical diversity of spirooxindoles via alkylative pyridine dearomatization. Beilstein J Org Chem 2012; 8:986-93. [PMID: 23019426 PMCID: PMC3458780 DOI: 10.3762/bjoc.8.111] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2012] [Accepted: 05/31/2012] [Indexed: 11/23/2022] Open
Abstract
A mild and practical synthesis of spirooxindole [1,3]oxazino derivatives from N-substituted isatins and 1,3-dicarbonyl compounds with pyridine derivatives is reported. The reactions provided good to excellent yields. Further exploration of the molecular diversity of these compounds is demonstrated through Diels–Alder reactions.
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94
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Dai C. Surgical Management for Patients with External Auditory Canal Carcinoma. Skull Base Surg 2012. [DOI: 10.1055/s-0032-1314240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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95
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Konieczynska MD, Dai C, Stephenson CRJ. Synthesis of symmetric anhydrides using visible light-mediated photoredox catalysis. Org Biomol Chem 2012; 10:4509-11. [PMID: 22573373 DOI: 10.1039/c2ob25463h] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A new approach to anhydride formation is reported via activation of C-O bonds by the Vilsmeier-Haack reagent formed by Ru(bpy)(3)Cl(2) and CBr(4) in DMF. Various aryl and alkyl carboxylic acids are converted to the corresponding anhydrides in excellent yields.
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96
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Dai C, Meschini F, Narayanam JMR, Stephenson CRJ. Friedel-Crafts amidoalkylation via thermolysis and oxidative photocatalysis. J Org Chem 2012; 77:4425-31. [PMID: 22458307 DOI: 10.1021/jo300162c] [Citation(s) in RCA: 149] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Friedel-Crafts amidoalkylation was achieved by oxidation of dialkylamides using persulfate (S(2)O(8)(2-)) in the presence of the visible light catalyst, Ru(bpy)(3)Cl(2), at room temperature, via a reactive N-acyliminium intermediate. Alternatively, mild heating of the dialkylamides and persulfate afforded a metal and Lewis acid-free Friedel-Crafts amidoalkylation. Alcohols and electron-rich arenes served as effective nucleophiles, forming new C-O or C-C bonds. In general, photocatalysis provided higher yields and better selectivities.
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97
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Dai C, Brissova M, Hang Y, Thompson C, Poffenberger G, Shostak A, Chen Z, Stein R, Powers AC. Islet-enriched gene expression and glucose-induced insulin secretion in human and mouse islets. Diabetologia 2012; 55:707-18. [PMID: 22167125 PMCID: PMC3268985 DOI: 10.1007/s00125-011-2369-0] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Accepted: 10/11/2011] [Indexed: 12/23/2022]
Abstract
AIMS/HYPOTHESIS Our understanding of the transcription factors that control the development and function of rodent islet beta cells is advancing rapidly, yet less is known of the role they play in similar processes in human islets. METHODS To characterise the abundance and regulation of key proteins involved in glucose-regulated insulin secretion in human islets, we examined the expression of MAFA, MAFB, GLUT2 (also known as SLC2A2), βGK (also known as GCK) and PDX1 in isolated, highly purified human islets with an intact insulin secretory pattern. We also assessed these features in islets from two different mouse strains (C57BL/6J and FVB). RESULTS Compared with mouse islets, human islets secreted more insulin at baseline glucose (5.6 mmol/l), but less upon stimulation with high glucose (16.7 mmol/l) or high glucose plus 3-isobutyl-1-methyl-xanthine. Human islets had relatively more MAFB than PDX1 mRNA, while mouse islets had relatively more Pdx1 than Mafb mRNA. However, v-maf musculoaponeurotic fibrosarcoma oncogene homologue (MAF) B protein was found in human islet alpha and beta cells. This is unusual as this regulator is only produced in islet alpha cells in adult mice. The expression of insulin, MAFA, βGK and PDX1 was not glucose-regulated in human islets with an intact insulin secretory pattern. CONCLUSIONS/INTERPRETATION Our results suggest that human islets have a distinctive distribution and function of key regulators of the glucose-stimulated insulin secretion pathway, emphasising the urgent need to understand the processes that regulate human islet beta cell function.
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Dai C, Li YP, Huang GH. A two-stage support-vector-regression optimization model for municipal solid waste management - a case study of Beijing, China. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2011; 92:3023-3037. [PMID: 21872384 DOI: 10.1016/j.jenvman.2011.06.038] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2011] [Revised: 06/07/2011] [Accepted: 06/21/2011] [Indexed: 05/31/2023]
Abstract
In this study, a two-stage support-vector-regression optimization model (TSOM) is developed for the planning of municipal solid waste (MSW) management in the urban districts of Beijing, China. It represents a new effort to enhance the analysis accuracy in optimizing the MSW management system through coupling the support-vector-regression (SVR) model with an interval-parameter mixed integer linear programming (IMILP). The developed TSOM can not only predict the city's future waste generation amount, but also reflect dynamic, interactive, and uncertain characteristics of the MSW management system. Four kernel functions such as linear kernel, polynomial kernel, radial basis function, and multi-layer perception kernel are chosen based on three quantitative simulation performance criteria [i.e. prediction accuracy (PA), fitting accuracy (FA) and over all accuracy (OA)]. The SVR with polynomial kernel has accurate prediction performance for MSW generation rate, with all of the three quantitative simulation performance criteria being over 96%. Two cases are considered based on different waste management policies. The results are valuable for supporting the adjustment of the existing waste-allocation patterns to raise the city's waste diversion rate, as well as the capacity planning of waste management system to satisfy the city's increasing waste treatment/disposal demands.
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Luther JM, Luo P, Kreger MT, Brissova M, Dai C, Whitfield TT, Kim HS, Wasserman DH, Powers AC, Brown NJ. Aldosterone decreases glucose-stimulated insulin secretion in vivo in mice and in murine islets. Diabetologia 2011; 54:2152-63. [PMID: 21519965 PMCID: PMC3216479 DOI: 10.1007/s00125-011-2158-9] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2011] [Accepted: 03/28/2011] [Indexed: 12/26/2022]
Abstract
AIMS/HYPOTHESIS Aldosterone concentrations increase in obesity and predict the onset of diabetes. We investigated the effects of aldosterone on glucose homeostasis and insulin secretion in vivo and in vitro. METHODS We assessed insulin sensitivity and insulin secretion in aldosterone synthase-deficient (As [also known as Cyp11b2](-/-)) and wild-type mice using euglycaemic-hyperinsulinaemic and hyperglycaemic clamps, respectively. We also conducted studies during high sodium intake to normalise renin activity and potassium concentration in As (-/-) mice. We subsequently assessed the effect of aldosterone on insulin secretion in vitro in the presence or absence of mineralocorticoid receptor antagonists in isolated C57BL/6J islets and in the MIN6 beta cell line. RESULTS Fasting glucose concentrations were reduced in As (-/-) mice compared with wild-type. During hyperglycaemic clamps, insulin and C-peptide concentrations increased to a greater extent in As (-/-) than in wild-type mice. This was not attributable to differences in potassium or angiotensin II, as glucose-stimulated insulin secretion was enhanced in As (-/-) mice even during high sodium intake. There was no difference in insulin sensitivity between As (-/-) and wild-type mice in euglycaemic-hyperinsulinaemic clamp studies. In islet and MIN6 beta cell studies, aldosterone inhibited glucose- and isobutylmethylxanthine-stimulated insulin secretion, an effect that was not blocked by mineralocorticoid receptor antagonism, but was prevented by the superoxide dismutase mimetic tempol. CONCLUSIONS/INTERPRETATION We demonstrated that aldosterone deficiency or excess modulates insulin secretion in vivo and in vitro via reactive oxygen species and in a manner that is independent of mineralocorticoid receptors. These findings provide insight into the mechanism of glucose intolerance in conditions of relative aldosterone excess.
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Dai C, Long Z, Xie Y, Xue S. Research on the filtering algorithm in speed and position detection of maglev trains. SENSORS 2011; 11:7204-18. [PMID: 22164012 PMCID: PMC3231682 DOI: 10.3390/s110707204] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/04/2011] [Revised: 06/30/2011] [Accepted: 07/13/2011] [Indexed: 11/16/2022]
Abstract
This paper introduces in brief the traction system of a permanent magnet electrodynamic suspension (EDS) train. The synchronous traction mode based on long stators and track cable is described. A speed and position detection system is recommended. It is installed on board and is used as the feedback end. Restricted by the maglev train's structure, the permanent magnet electrodynamic suspension (EDS) train uses the non-contact method to detect its position. Because of the shake and the track joints, the position signal sent by the position sensor is always aberrant and noisy. To solve this problem, a linear discrete track-differentiator filtering algorithm is proposed. The filtering characters of the track-differentiator (TD) and track-differentiator group are analyzed. The four series of TD are used in the signal processing unit. The result shows that the track-differentiator could have a good effect and make the traction system run normally.
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