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Sun J, Gu C, Zhang C, Lei C, Fang X, Jin Q, Chen D, Shi X, Du Y, Chen H. Association of polymorphisms of the <i>DCN</i> gene with growth traits in cattle (Brief Report). Arch Anim Breed 2010. [DOI: 10.5194/aab-53-119-2010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Abstract. Mammalian decorin (DCN) consists of a protein core and a single dermatan or chondroitin sulfate glycosaminoglycan chain (CHOPRA et al. 1985), contributing multifunctionally to processes like matrix assembly, modulation of the activity of growth factors and cell migration and proliferation. Recently, LINDA et al. (2008) have reported that eight SNPs were identified in human. However, the related information in bovine is scarce. Hence, in the present experiment the exons and intron/exon boundaries of DCN were scanned for SNPs in the predominant cattle breeds of China.
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Gao L, Tao Y, Zhang L, Jin Q. Vitamin D receptor genetic polymorphisms and tuberculosis: updated systematic review and meta-analysis. Int J Tuberc Lung Dis 2010; 14:15-23. [PMID: 20003690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023] Open
Abstract
BACKGROUND Host genetic susceptibility has been suggested as one of the most important explanations for inter-individual differences in tuberculosis (TB) risk. The vitamin D receptor (VDR) gene has been studied as a candidate locus due to genetic polymorphisms that affects the activity of the receptor and subsequent downstream vitamin D-mediated effects. METHODS We reviewed published studies on VDR polymorphisms and TB susceptibility up to 15 April 2009 and quantitatively summarised associations of the most widely studied polymorphisms (FokI, TaqI, ApaI and BsmI) using meta-analysis. RESULTS A total of 23 eligible studies were included in this review. Heterogeneous results were observed, which may be partly explained by the differences between populations. Among Asians, the FokI ff genotype showed a pronounced positive association (OR 2.0, 95%CI 1.3-3.2), a significant inverse association was observed for the BsmI bb genotype (OR 0.5, 95%CI 0.4-0.8), and marginal significant associations were found for TaqI and ApaI polymorphisms. However, none of the polymorphisms was significantly related to TB among Africans or South Americans. CONCLUSIONS The association of VDR polymorphisms with risk of TB observed in our analyses supports the hypothesis that vitamin D deficiency might play a role as risk factor during the development of TB.
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Li X, Xie C, Jin Q, Liu M, He Q, Cao R, Lin Y, Li J, Li Y, Chen P, Liang S. Proteomic screen for multiprotein complexes in synaptic plasma membrane from rat hippocampus by blue native gel electrophoresis and tandem mass spectrometry. J Proteome Res 2009; 8:3475-86. [PMID: 19432478 DOI: 10.1021/pr900101d] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Neuronal synapses are specialized sites for information exchange between neurons. Many diseases, such as addiction and mood disorders, likely result from altered expression of synaptic proteins, or altered formation of synaptic complexes involved in neurotransmission or neuroplasticity. A detailed description of native multiprotein complexes in synaptic plasma membranes (PM) is therefore essential for understanding biological mechanisms and disease processes. For the first time in this study, two-dimensional Blue Native/SDS-PAGE electrophoresis, combined with tandem mass spectrometry, was used to screen multiprotein complexes in synaptic plasma membranes from rat hippocampus. As a result, 514 unique proteins were identified, of which 36% were integral membrane proteins. In addition, 19 potentially novel and known heterooligomeric multiprotein complexes were found, such as the SNARE and ATPase complexes. A potentially novel protein complex, involving syntaxin, synapsin I and Na+/K+ ATPase alpha-1, was further confirmed by co-immunoprecipitation and immunofluorescence staining. As demonstrated here, Blue Native-PAGE is a powerful tool for the separation of hydrophobic membrane proteins. The combination of Blue Native-PAGE and mass spectrometry could systematically identify multiprotein complexes.
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Chang PC, Seol YJ, Cirelli JA, Pellegrini G, Jin Q, Franco LM, Goldstein SA, Chandler LA, Sosnowski B, Giannobile WV. PDGF-B gene therapy accelerates bone engineering and oral implant osseointegration. Gene Ther 2009; 17:95-104. [PMID: 19741730 PMCID: PMC2803328 DOI: 10.1038/gt.2009.117] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Platelet-derived growth factor-BB (PDGF-BB) stimulates repair of healing-impaired chronic wounds such as diabetic ulcers and periodontal lesions. However, limitations in predictability of tissue regeneration occur due in part to transient growth factor bioavailability in vivo. Here, we report that gene delivery of PDGF-B stimulates repair of oral implant extraction socket defects. Alveolar ridge defects were created in rats and were treated at the time of titanium implant installation with a collagen matrix containing an adenoviral (Ad) vector encoding PDGF-B (5.5×108 or 5.5×109 pfu/ml), Ad encoding luciferase (Ad-Luc; 5.5×109 pfu/ml; control) or recombinant human PDGF-BB protein (rhPDGF-BB, 0.3 mg/ml). Bone repair and osseointegration were measured via backscattered SEM, histomorphometry, microcomputed tomography, and biomechanical assessments. Further, a panel of local and systemic safety assessments was performed. Results demonstrated bone repair was accelerated by Ad-PDGF-B and rhPDGF-BB delivery compared to Ad-Luc, with the high dose of Ad-PDGF-B more effective than the low dose. No significant dissemination of the vector construct or alteration of systemic parameters was noted. In summary, gene delivery of Ad-PDGF-B demonstrates regenerative and safety capabilities for bone tissue engineering and osseointegration in alveolar bone defects comparable to rhPDGF-BB protein delivery in vivo.
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80
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Han N, Seo E, Jin Q. Marking bio-information in the genome of lactic acid bacteria by random integration of DNA barcode. N Biotechnol 2009. [DOI: 10.1016/j.nbt.2009.06.699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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81
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Ren L, Gonzalez R, Wang Z, Xiang Z, Wang Y, Zhou H, Li J, Xiao Y, Yang Q, Zhang J, Chen L, Wang W, Li Y, Li T, Meng X, Zhang Y, Vernet G, Paranhos-Baccalà G, Chen J, Jin Q, Wang J. Prevalence of human respiratory viruses in adults with acute respiratory tract infections in Beijing, 2005-2007. Clin Microbiol Infect 2009; 15:1146-53. [PMID: 19456830 PMCID: PMC7129754 DOI: 10.1111/j.1469-0691.2009.02746.x] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
To determine the aetiological role and epidemiological profile of common respiratory viruses in adults with acute respiratory tract infections (ARTIs), a 2-year study was conducted in Beijing, China, from May 2005 to July 2007. Nose and throat swab samples from 5808 ARTI patients were analysed by PCR methods for common respiratory viruses, including influenza viruses (IFVs) A, B, and C, parainfluenza viruses (PIVs) 1-4, enteroviruses (EVs), human rhinoviruses (HRVs), respiratory syncytial virus (RSV), human metapneumovirus (HMPV), human coronaviruses (HCoVs) OC43, 229E, NL63, and HKU1, and adenoviruses (ADVs). Viral pathogens were detected in 34.6% of patient samples, and 1.6% of the patients tested positive for more than one virus. IFVs (19.3%) were the dominant agents detected, followed by HRVs (6.5%), PIVs (4.3%), EVs (3.2%), and HCoVs (1.1%). ADVs, RSV and HMPV were also detected (<1%). The viral detection rates differed significantly between infections of the lower and upper respiratory tracts in the sample population: PIVs, the second most commonly detected viral agents in lower acute respiratory tract infections (LRTIs), were more prevalent than in upper acute respiratory tract infections, indicating that the pathogenic role of PIVs in LRTIs should be investigated. Currently, this study is the largest-scale investigation of respiratory virus infections in China with multiple agent detection, providing baseline data for further studies of respiratory virus infections in adults with ARTIs.
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Gao L, Zhang L, Jin Q. Meta-analysis: prevalence of HIV infection and syphilis among MSM in China. Sex Transm Infect 2009; 85:354-8. [PMID: 19351623 DOI: 10.1136/sti.2008.034702] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
OBJECTIVES The prevalence of HIV/AIDS and other sexually transmitted diseases is rapidly rising among men who have sex with men (MSM) in China. The aim is to systematically review the published studies and summarise the estimates of HIV prevalence among MSM in China. METHODS Published articles, both in English and in Chinese, on HIV prevalence among MSM in China until 15 September 2008 were systematically reviewed. Meta-analysis was used to quantitatively summarise the estimates, and the prevalence of syphilis presented in the included studies was also analysed. RESULTS Twenty-six eligible studies, published during 2001-2008, were included in this review. Their results were frequently heterogeneous. The meta-analyses showed that MSM form a high-risk population for HIV infection in China with a summary prevalence of 2.5% (95% CI 0.9% to 3.3%). A much higher prevalence of syphilis (9.1%) may indicate a potential of more severe HIV epidemic in the future because of their common high-risk behaviours. CONCLUSIONS MSM are a high-risk population for HIV infection in China. An effective strategy for prevention and control is required for this specific population. Differences between sampling methods, sample sizes and study locations may explain some of the inconsistencies found in the included studies.
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Li X, Jin Q, Cao J, Xie C, Cao R, Liu Z, Xiong J, Li J, Yang X, Chen P, Liang S. Evaluation of two cell surface modification methods for proteomic analysis of plasma membrane from isolated mouse hepatocytes. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2009; 1794:32-41. [DOI: 10.1016/j.bbapap.2008.07.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2008] [Revised: 07/09/2008] [Accepted: 07/09/2008] [Indexed: 01/13/2023]
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84
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Li X, Xie C, Cao J, He Q, Cao R, Lin Y, Jin Q, Chen P, Wang X, Liang S. An in Vivo Membrane Density Perturbation Strategy for Identification of Liver Sinusoidal Surface Proteome Accessible from the Vasculature. J Proteome Res 2008; 8:123-32. [DOI: 10.1021/pr8006683] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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85
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Lin Z, Sugai JV, Jin Q, Chandler LA, Giannobile WV. Platelet-derived growth factor-B gene delivery sustains gingival fibroblast signal transduction. J Periodontal Res 2008; 43:440-9. [PMID: 18823454 DOI: 10.1111/j.1600-0765.2008.01089.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND AND OBJECTIVE Platelet-derived growth factor-BB is a potent mediator of tooth-supporting periodontal tissue repair and regeneration. A limitation of the effects of topical platelet-derived growth factor-BB application is its short half-life in vivo. Gene therapy has shown strong promise for the long-term delivery of platelet-derived growth factor in both skin ulcer healing and periodontal tissue engineering. However, little is known regarding the extended effects of platelet-derived growth factor-B on cell signaling via gene delivery, especially at the level of phosphorylation of intracellular kinases. This study sought to evaluate the effect of gene transfer by Ad-PDGF-B on human gingival fibroblasts (HGFs) and the subsequent regulation of genes and cell-surface proteins associated with cellular signaling. MATERIAL AND METHODS HGFs from human subjects were treated by adenoviral PDGF-B, PDGF-1308 (a dominant negative mutant of PDGF) and recombinant human platelet-derived growth factor-BB, and then incubated in serum-free conditions for various time points and harvested at 1, 6, 12, 24, 48, 72 and 96 h. Exogenous PDGF-B was measured by RT-PCR and Western blot. Cell proliferation was evaluated by [methyl-3H]thymidine incorporation assay. We used proteomic arrays to explore phosphorylation patterns of 23 different intracellular kinases after PDGF-B gene transfer. The expression of alpha and beta PDGFR and Akt were measured by Western blot analysis. RESULTS Sustained in vitro expression of PDGF-B in HGFs by Ad-PDGF-B transduction was seen at both the mRNA and protein levels. Compared to rhPDGF-BB and Ad-PDGF-1308, Ad-PDGF-B maintained cell growth in serum-free conditions, with robust increases in DNA synthesis. Gene delivery of PDGF-B also prolonged downregulation of the growth arrest specific gene (gas) PDGF alpha R. Of the 23 intracellular kinases that we tested in proteomic arrays, Akt revealed the most notable long-term cell signaling effect as a result of the over-expression of Ad-PDGF-B, compared with pulse recombinant human platelet-derived growth factor BB. Prolonged Akt phosphorylation was induced by treatment with Ad-PDGF-B, for at least up to 96 h. CONCLUSION These findings further demonstrate that gene delivery of PDGF-B displays sustained signal transduction effects in human gingival fibroblasts that are higher than those conveyed by treatment with recombinant human platelet-derived growth factor-BB protein. These data on platelet-derived growth factor gene delivery contribute to an improved understanding of these pathways that are likely to play a role in the control of clinical outcomes of periodontal regenerative therapy.
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Li X, Cao J, Jin Q, Xie C, He Q, Cao R, Xiong J, Chen P, Wang X, Liang S. A proteomic study reveals the diversified distribution of plasma membrane-associated proteins in rat hepatocytes. J Cell Biochem 2008; 104:965-84. [PMID: 18247341 DOI: 10.1002/jcb.21680] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
To investigate the heterogeneous protein composition of highly polarized hepatocyte plasma membrane (PM), three PM-associated subfractions were obtained from freshly isolated rat hepatocytes using density gradient centrifugation. The origins of the three subfractions were determined by morphological analysis and western blotting. The proteins were subjected to either one-dimensional (1-D) SDS-PAGE or two-dimensional (2-D) benzyldimethyl-n-hexadecylammonium chloride (BAC)/SDS-PAGE before nano-Liquid Chromatography-Electrospray Ionization--tandem mass spectrometry analysis (LC-ESI-MS/MS). A total of 613 non-redundant proteins were identified, among which 371 (60.5%) proteins were classified as PM or membrane-associated proteins according to GO annotations and the literatures and 32.4% had transmembrane domains. PM proteins from microsomal portion possessed the highest percentage of transmembrane domain, about 46.5% of them containing at least one transmembrane domain. In addition to proteins known to be located at polarized liver PM regions, such as asialoglycoprotein receptor 2, desmoplakin and bile salt export pump, several proteins which had the potential to become novel subfraction-specific proteins were also identified, such as annexin a6, pannexin and radixin. Our analysis also evaluated the application of 1-D SDS-PAGE and 2-D 16-BAC/SDS-PAGE on the separation of integral membrane proteins.
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Zhang X, Shao Z, Zhu Y, Xu L, Xu X, Mayer L, Xu J, Jin Q. Genetic characteristics of serogroup A meningococci circulating in China, 1956–2005. Clin Microbiol Infect 2008; 14:555-61. [DOI: 10.1111/j.1469-0691.2008.01977.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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88
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William WN, Jin Q, Kim ES, Feng L, Prudkin L, Lee JJ, Behrens C, Wistuba II, Lee H. Expression of phospho(p)-AMP-activated protein kinase (AMPK) in lung cancer. J Clin Oncol 2008. [DOI: 10.1200/jco.2008.26.15_suppl.11085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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89
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Yu L, Zhang W, Liu T, Wang X, Peng J, Li S, Jin Q. Global gene expression of Trichophyton rubrum in response to PH11B, a novel fatty acid synthase inhibitor. J Appl Microbiol 2008; 103:2346-52. [PMID: 18045420 DOI: 10.1111/j.1365-2672.2007.03521.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIMS To determine the transcriptional responses of Trichophyton rubrum to the artificial substance, PH11B. METHODS AND RESULTS The broth microdilution assay for antifungal susceptibility testing of dermatophytes was used to measure the minimum inhibitory concentration (MIC) of PH11B. cDNA microarray technology and real-time RT-PCR were used to study the transcriptional responses of T. rubrum to PH11B. The MIC determined was 16 microg ml(-1). The analysis of microarray data revealed that 787 genes were affected. Transcript levels from 476 genes increased at least two times, while 311 gene transcript levels decreased at least two times. CONCLUSIONS PH11B has strong antifungal activity and the transcriptional response of T. rubrum to PH11B was determined. SIGNIFICANCE AND IMPACT OF THE STUDY This microarray data set provides an analysis of gene expression of T. rubrum under PH11B treatment. The data provide an insight into the various metabolic processes altered or activated by PH11B. This study provided an insight into the action mode of the PH11B on T. rubrum.
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Jin Q, Feng L, Behrens C, Bekele BN, Wistuba II, Hong WK, Lee HY. Implication of AMP-Activated Protein Kinase and Akt-Regulated Survivin in Lung Cancer Chemopreventive Activities of Deguelin. Cancer Res 2007; 67:11630-9. [DOI: 10.1158/0008-5472.can-07-2401] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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91
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Malnoy M, Jin Q, Borejsza-Wysocka EE, He SY, Aldwinckle HS. Overexpression of the apple MpNPR1 gene confers increased disease resistance in Malus x domestica. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2007; 20:1568-80. [PMID: 17990964 DOI: 10.1094/mpmi-20-12-1568] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
The NPR1 gene plays a pivotal role in systemic acquired resistance in plants. Its overexpression in Arabidopsis and rice results in increased disease resistance and elevated expression of pathogenesis-related (PR) genes. An NPR1 homolog, MpNPR1-1, was cloned from apple (Malus x domestica) and overexpressed in two important apple cultivars, Galaxy and M26. Apple leaf pieces were transformed with the MpNPR1 cDNA under the control of the inducible Pin2 or constitutive Cauliflower mosaic virus (CaMV)35S promoter using Agrobacterium tumefaciens. Overexpression of MpNPR1 mRNA was shown by reverse transcriptase-polymerase chain reaction. Activation of some PR genes (PR2, PR5, and PR8) was observed. Resistance to fire blight was evaluated in a growth chamber by inoculation of the shoot tips of our own rooted 30-cm-tall plants with virulent strain Ea273 of Erwinia amylovora. Transformed Galaxy lines overexpressing MpNPR1 had 32 to 40% of shoot length infected, compared with 80% in control Galaxy plants. Transformed M26 lines overexpressing MpNPR1 under the control of the CaMV35S promoter also showed a significant reduction of disease compared with control M26 plants. Some MpNPR-overexpressing Galaxy lines also exhibited increased resistance to two important fungal pathogens of apple, Venturia inaequalis and Gymnosporangium juniperi-virginianae. Selected transformed lines have been propagated for field trials for disease resistance and fruit quality.
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92
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Yuan C, Jin Q, Tang X, Hu W, Cao R, Yang S, Xiong J, Xie C, Xie J, Liang S. Proteomic and peptidomic characterization of the venom from the Chinese bird spider, Ornithoctonus huwena Wang. J Proteome Res 2007; 6:2792-801. [PMID: 17567163 DOI: 10.1021/pr0700192] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The bird spider Ornithoctonus huwena Wang is a very venomous spider in China. Several compounds with different types of biological activities have been identified previously from the venom of this spider. In this study, we have performed a proteomic and peptidomic analysis of the venom. The venom was preseparated into two parts: the venom proteins with molecular weight (MW) higher than 10,000 and the venom peptides with MW lower than 10 000. Using one-dimensional gel electrophoresis (1-DE), two-dimensional gel electrophoresis (2-DE), and mass spectrometry, 90 proteins were identified, including some important enzymes, binding proteins, and some proteins with significant biological functions. For venom peptides, a combination of cation-exchange and reversed-phase chromatography was employed. More than 100 components were detected by mass spectrometry, and 47 peptides were sequenced by Edman degradation. The peptides display structural and pharmacological diversity and share little sequence similarity with peptides from other animal venoms, which indicates the venom of O. huwena Wang is unique. The venom peptides can be classified into several superfamilies. Also it is revealed that gene duplication and focal hypermutation have taken place during the evolution of the spider toxins.
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Jin Q. Control of hydrogen partial pressures on the rates of syntrophic microbial metabolisms: a kinetic model for butyrate fermentation. GEOBIOLOGY 2007; 5:35-48. [PMID: 36298874 DOI: 10.1111/j.1472-4669.2006.00090.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
A new model describing the rate of syntrophic butyrate fermentation is constructed based on a thermodynamically consistent rate law and the metabolic pathway. This model takes into account the mechanism of reverse electron transfer and proposes that the net amount of energy saved by microorganisms as ATP depends on hydrogen partial pressures in the environment. Hydrogen partial pressures thus control not only the energy available in the environment but also the energy conserved by microorganisms. This new model predicts the rates of butyrate fermentation as a product of a kinetic factor and a thermodynamic potential factor: the kinetic factor describes how butyrate concentration controls the rates; the thermodynamic factor accounts for how the thermodynamic driving force controls the rates. Increases in hydrogen partial pressures decrease the energy available, lowering the driving force and fermentation rates. To maintain butyrate fermentation at significant rates, microorganisms decrease the amount of energy conserved, maximizing the driving force. Application of the new model demonstrates that the thermodynamic driving force is a dominant factor in controlling the rates of butyrate fermentation.
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94
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Zhang J, Jin Q, Xu Y. Inferential Estimation of Polymer Melt Index Using Sequentially Trained Bootstrap Aggregated Neural Networks. Chem Eng Technol 2006. [DOI: 10.1002/ceat.200500352] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Abstract
[reaction: see text] Dirhodium tetrakis((S)-N-dodecylbenzenesulfonyl)prolinate) (Rh2(S-DOSP)4) catalyzed reaction of 1,2-dihydronaphthalenes with an excess of methyl vinyldiazoacetates results in a formal double C-H activation, generating four new stereogenic centers with very high stereoselectivity. The mechanism of the C-H activation is complex, involving a combined C-H activation/Cope rearrangement followed by a retro-Cope rearrangement.
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Abstract
Repair of tooth supporting alveolar bone defects caused by periodontal and peri-implant tissue destruction is a major goal of reconstructive therapy. Oral and craniofacial tissue engineering has been achieved with limited success by the utilization of a variety of approaches such as cell-occlusive barrier membranes, bone substitutes and autogenous block grafting techniques. Signaling molecules such as growth factors have been used to restore lost tooth support because of damage by periodontal disease or trauma. This paper will review emerging periodontal therapies in the areas of materials science, growth factor biology and cell/gene therapy. Several different polymer delivery systems that aid in the targeting of proteins, genes and cells to periodontal and peri-implant defects will be highlighted. Results from preclinical and clinical trials will be reviewed using the topical application of bone morphogenetic proteins (BMP-2 and BMP-7) and platelet-derived growth factor-BB (PDGF) for periodontal and peri-implant regeneration. The paper concludes with recent research on the use of ex vivo and in vivo gene delivery strategies via gene therapy vectors encoding growth promoting and inhibiting molecules (PDGF, BMP, noggin and others) to regenerate periodontal structures including bone, periodontal ligament and cementum.
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Davies HML, Jin Q. Double C-H activation strategy for the asymmetric synthesis of C2-symmetric anilines. Org Lett 2004; 6:1769-72. [PMID: 15151410 DOI: 10.1021/ol0495467] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Rh(2)(S-DOSP)(4)-catalyzed C-H activation to N,N-dimethylanilines is described. A double C-H activation was possible by using an excess of methyl aryldiazoacetate, and this provided a very direct approach to C(2)-symmetric anilines. [reaction--see text]
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Davies HML, Jin Q. Highly Diastereoselective and Enantioselective C−H Functionalization of 1,2-Dihydronaphthalenes: A Combined C−H Activation/Cope Rearrangement Followed by a Retro-Cope Rearrangement. J Am Chem Soc 2004; 126:10862-3. [PMID: 15339169 DOI: 10.1021/ja047185k] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The Rh2(S-DOSP)4-catalyzed reaction of vinyldiazoacetates with dihydronaphthalenes results in a highly enantioselective (91-99.6% ee) and diastereoselective (>98% de) C-H functionalization. The apparent intermolecular C-H insertion was demonstrated to be a combined C-H activation/Cope rearrangement followed by a retro-Cope rearrangement.
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Davies HML, Jin Q. Catalytic asymmetric reactions for organic synthesis: the combined C-H activation/Cope rearrangement. Proc Natl Acad Sci U S A 2004; 101:5472-5. [PMID: 15024094 PMCID: PMC397407 DOI: 10.1073/pnas.0307556101] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The development of new catalytic asymmetric reactions can lead to exciting new strategies for organic synthesis. This article describes the synthetic utility of the combined C-H activation/Cope rearrangement, achieved by dirhodium tetraprolinate-catalyzed reaction of vinyldiazoacetates with compounds containing allylic C-H bonds. The transformation is highly diastereoselective and enantioselective. The product distribution, however, is highly substrate dependent, the major side products being either direct C-H activation or cyclopropanation.
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Davies HML, Beckwith REJ, Antoulinakis EG, Jin Q. New strategic reactions for organic synthesis: catalytic asymmetric C-H activation alpha to oxygen as a surrogate to the aldol reaction. J Org Chem 2003; 68:6126-32. [PMID: 12895040 DOI: 10.1021/jo034533c] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The C-H activation of silyl ethers by means of rhodium carbenoid-induced C-H insertion represents a very direct method for the stereoselective synthesis of silyl-protected beta-hydroxy esters. The reaction can proceed with very high regio-, diastereo-, and enantioselectivity and represents a surrogate to the aldol reaction. The reaction is catalyzed by the rhodium prolinate complex Rh(2)(S-DOSP)(4). A critical requirement for the high chemoselectivity is the use of donor/acceptor-substituted carbenoids such as those derived from methyl aryldiazoacetates. A range of silyl ethers may be used such as allyl silyl ethers, tetraalkoxysilanes, and even simple trimethylsilyl alkyl ethers. In general, C-H activation preferentially occurs at methylene sites, as the reactivity is controlled by a delicate balance between steric and electronic effects.
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