Coals consist of some molecules trapped within an organic matrix from which some organic compounds can be extracted by solvents. The Soxhlet technique has been widely used for extracting organic compounds. Microwave h...Coals consist of some molecules trapped within an organic matrix from which some organic compounds can be extracted by solvents. The Soxhlet technique has been widely used for extracting organic compounds. Microwave heating methods may be successfully applied in the field of coal science. Acetone extraction yields and the chemical composition of the extract were investigated using a typical Chinese coal, Shenfu coal, with microwave-assisted extraction. The acetone extract and residue were analyzed by GC/MS and carbon-13 nuclear magnetic resonance spectroscopy respectively. The carbon spectra were converted into several numerical parameters, fa, Ha, Xb, which indicate the difference in macromolecular structure between Shenfu coal and its residue. Furthermore, a hybrid genetic algorithm was employed using these parameters to approximate a coal macromolecule by assembling the structural fragments or functional groups into a large and complicated structure.展开更多
Previous investigation on the mutagenic effects of 3,N4-Ethenocytosine (εC), a nonpairing DNA lesion,revealed the existence of a novel SOS-independent inducible mutagenic mechanism in E. coli termed UVM for UV modula...Previous investigation on the mutagenic effects of 3,N4-Ethenocytosine (εC), a nonpairing DNA lesion,revealed the existence of a novel SOS-independent inducible mutagenic mechanism in E. coli termed UVM for UV modulation of mutagenesis. To investigate whether UVM is mediated by an alteration of DNA replication, we have set up an in vitro replication system ill which phage M13 viral single-stranded DNA bearing a single site-specific (εC) residue is replicated by soluble protein extracts from E. coli cells. Replication products were analyzed by agarose gel electrophoresis and the frequency of translesion synthesis was determined by restriction endonuclease analyses. Our data indicate that DNA replication is strongly inhibited by εC, but that translesion DNA synthesis does occur in about 14% of the replicated DNA molecules. These results are very similar to those observed previously in vivo, and suggest that this experimental system may be suitable for evaluating alterations in DNA replication in UVM-induced cells.展开更多
Extracts of plant origin,particularly tannins,are attracting growing interest for the sustainable development of materials in the industrial sector.The discovery of new tannins is therefore necessary.The aim of this w...Extracts of plant origin,particularly tannins,are attracting growing interest for the sustainable development of materials in the industrial sector.The discovery of new tannins is therefore necessary.The aim of this work was to contribute to the understanding of the properties of Paraberlinia bifoliolata tannin by Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectroscopy MALDI-TOF/MS and Carbon 13 Nuclear Magnetic Resonance(13C NMR).The chemical composition of tannin extracted from Paraberlinia bifoliolata bark was determined,as was the mechanical strength of the resin hardened with Acacia nilotica extracts.Yield by successive water extraction was 35%.MALDI-TOF/MS analysis revealed the presence of three new compounds in this tannin,previously unknown in this family of extracts.These are 3-hydroxyproline acid,N-methyl-4-hydroxypipecolic acid and N-methyl-5-dihydroxypipecolic acid.The identification of the above molecules means that this tannin can be used for industrial applications,as a resin in the manufacture of particleboard and in the formulation of green corrosion inhibitors.This information is reinforced by 13C NMR spectrometry,which indicates the presence of several polyflavonoid units,confirming the condensed nature of the tannin.Thermomechanical analysis of the resin formed by the purified tannin of Paraberlinia bifoliolata to which a vegetal biohardener has been added provided a Modulus of Elasticity(MOE)value of 4840 MPa at 150℃,confirming its possible use as a binder resin in the manufacture of wood panels as well as for the formulation of a corrosion inhibitor.展开更多
采用热重分析(TGA)和傅里叶红外光谱(FTIR)联用实验技术以及13 C核磁共振(13 C NMR)技术,详细研究了印尼油砂热解产气过程和油砂沥青质的化学结构变化。油砂热解产气的TG-FTIR分析显示,油砂热解过程可以分为水分蒸发段(0~150℃)、低温段...采用热重分析(TGA)和傅里叶红外光谱(FTIR)联用实验技术以及13 C核磁共振(13 C NMR)技术,详细研究了印尼油砂热解产气过程和油砂沥青质的化学结构变化。油砂热解产气的TG-FTIR分析显示,油砂热解过程可以分为水分蒸发段(0~150℃)、低温段(150~550℃)和高温段(550~800℃)3个阶段,油气的析出主要集中在低温段,样品失重量为21%;在低温段所得油气的主要红外吸收峰归属于亚甲基和次甲基的C—H伸缩振动以及甲基的C—H面内弯曲振动。采用13C NMR技术获得了不同终温下沥青质碳结构骨架参数,由此揭示出油砂热解过程中化学结构的变化规律。随着油砂热解温度升高,沥青质中芳香族碳数量略有增加,脂肪族碳数量减少,其中亚甲基碳数量大幅度减小,是产油的主要贡献者,但甲基碳数量变化不明显;脂链平均长度不断减小,从9.2下降到4.0;油潜力碳的比例由0.56下降到0.27;在热解末期即产油能力最低时,惰性碳的比例占到0.6。2种实验结果相互印证且吻合良好。展开更多
The resveratrol-enriched transgenic rice line Iksan526(IS526),first developed by the Rural Development Administration of Korea using genetic engineering techniques,shows beneficial health effects in mitigating metabol...The resveratrol-enriched transgenic rice line Iksan526(IS526),first developed by the Rural Development Administration of Korea using genetic engineering techniques,shows beneficial health effects in mitigating metabolic syndrome and obesity.However,the effects of IS526 on the differentiation of chondrocytes and the underlying mechanism have not been investigated in detail.In this study,the effects and cellular regulatory mechanisms of IS526 on rabbit articular chondrocytes were examined.Following IS526 callus extract treatment,the expression levels of differentiation-related proteins were detected via western blotting,Alcian blue staining and immune-luorescence staining.IS526 decreased the type Ⅱ collagen and proteoglycan levels in dose-and time-dependent manners.We further analyzed the effects of IS526 on skeleton genesis in zebrafish larvae using Alcian blue staining,which showed a reduction in cartilage formation along with increased production of matrix metalloproteinase(MMP)-13.IS526 also increased the phosphorylation of ERK1/2 and p38 kinase but inhibited the phosphorylation of Akt.Pharmacological inhibition of MMP-13 blocked the IS526-induced decrease in type Ⅱ collagen levels.Inhibition of p38 kinase or PI-3K/Akt with SB203580 and LY294002 enhanced the suppression of type Ⅱ collagen,but the blockage of ERK-1/2 by PD98059 rescued IS526-induced dedifferentiation.These results suggested that IS526 regulates type Ⅱ collagen and MMP-13 expression via the ERK1/2 and PI-3K/Akt pathways in rabbit articular chondrocytes.展开更多
基金Project 40472082 supported by the National Natural Science Foundation of China
文摘Coals consist of some molecules trapped within an organic matrix from which some organic compounds can be extracted by solvents. The Soxhlet technique has been widely used for extracting organic compounds. Microwave heating methods may be successfully applied in the field of coal science. Acetone extraction yields and the chemical composition of the extract were investigated using a typical Chinese coal, Shenfu coal, with microwave-assisted extraction. The acetone extract and residue were analyzed by GC/MS and carbon-13 nuclear magnetic resonance spectroscopy respectively. The carbon spectra were converted into several numerical parameters, fa, Ha, Xb, which indicate the difference in macromolecular structure between Shenfu coal and its residue. Furthermore, a hybrid genetic algorithm was employed using these parameters to approximate a coal macromolecule by assembling the structural fragments or functional groups into a large and complicated structure.
文摘Previous investigation on the mutagenic effects of 3,N4-Ethenocytosine (εC), a nonpairing DNA lesion,revealed the existence of a novel SOS-independent inducible mutagenic mechanism in E. coli termed UVM for UV modulation of mutagenesis. To investigate whether UVM is mediated by an alteration of DNA replication, we have set up an in vitro replication system ill which phage M13 viral single-stranded DNA bearing a single site-specific (εC) residue is replicated by soluble protein extracts from E. coli cells. Replication products were analyzed by agarose gel electrophoresis and the frequency of translesion synthesis was determined by restriction endonuclease analyses. Our data indicate that DNA replication is strongly inhibited by εC, but that translesion DNA synthesis does occur in about 14% of the replicated DNA molecules. These results are very similar to those observed previously in vivo, and suggest that this experimental system may be suitable for evaluating alterations in DNA replication in UVM-induced cells.
基金supported by the Institut de la Francophonie pour le Developpement Durable(IFDD/Canada)/Projet de Deploiement des Technologies et Innovations Environnementales(PDTIE)funded by Organisation Internationale de la Francophonie(OIF)the Organisation of African,Caribbean and Pacific States and the European Union(EU)(FED/220/421-370)the Local Materials Promotion Authority(MIPROMALO)of the Ministry of Scientific Research and Innovation of Cameroon who made it possible for this scientific work to be carried out.
文摘Extracts of plant origin,particularly tannins,are attracting growing interest for the sustainable development of materials in the industrial sector.The discovery of new tannins is therefore necessary.The aim of this work was to contribute to the understanding of the properties of Paraberlinia bifoliolata tannin by Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectroscopy MALDI-TOF/MS and Carbon 13 Nuclear Magnetic Resonance(13C NMR).The chemical composition of tannin extracted from Paraberlinia bifoliolata bark was determined,as was the mechanical strength of the resin hardened with Acacia nilotica extracts.Yield by successive water extraction was 35%.MALDI-TOF/MS analysis revealed the presence of three new compounds in this tannin,previously unknown in this family of extracts.These are 3-hydroxyproline acid,N-methyl-4-hydroxypipecolic acid and N-methyl-5-dihydroxypipecolic acid.The identification of the above molecules means that this tannin can be used for industrial applications,as a resin in the manufacture of particleboard and in the formulation of green corrosion inhibitors.This information is reinforced by 13C NMR spectrometry,which indicates the presence of several polyflavonoid units,confirming the condensed nature of the tannin.Thermomechanical analysis of the resin formed by the purified tannin of Paraberlinia bifoliolata to which a vegetal biohardener has been added provided a Modulus of Elasticity(MOE)value of 4840 MPa at 150℃,confirming its possible use as a binder resin in the manufacture of wood panels as well as for the formulation of a corrosion inhibitor.
文摘采用热重分析(TGA)和傅里叶红外光谱(FTIR)联用实验技术以及13 C核磁共振(13 C NMR)技术,详细研究了印尼油砂热解产气过程和油砂沥青质的化学结构变化。油砂热解产气的TG-FTIR分析显示,油砂热解过程可以分为水分蒸发段(0~150℃)、低温段(150~550℃)和高温段(550~800℃)3个阶段,油气的析出主要集中在低温段,样品失重量为21%;在低温段所得油气的主要红外吸收峰归属于亚甲基和次甲基的C—H伸缩振动以及甲基的C—H面内弯曲振动。采用13C NMR技术获得了不同终温下沥青质碳结构骨架参数,由此揭示出油砂热解过程中化学结构的变化规律。随着油砂热解温度升高,沥青质中芳香族碳数量略有增加,脂肪族碳数量减少,其中亚甲基碳数量大幅度减小,是产油的主要贡献者,但甲基碳数量变化不明显;脂链平均长度不断减小,从9.2下降到4.0;油潜力碳的比例由0.56下降到0.27;在热解末期即产油能力最低时,惰性碳的比例占到0.6。2种实验结果相互印证且吻合良好。
基金This work was supported by the National Research Foundation of Korea funded by the Korean Government(Grant No.2017R1D1A3B03033401)the Center for Women in Science,Engineering and Technology Grant funded by the Ministry of Science and ICT under the Program for Returners into Research and Development.
文摘The resveratrol-enriched transgenic rice line Iksan526(IS526),first developed by the Rural Development Administration of Korea using genetic engineering techniques,shows beneficial health effects in mitigating metabolic syndrome and obesity.However,the effects of IS526 on the differentiation of chondrocytes and the underlying mechanism have not been investigated in detail.In this study,the effects and cellular regulatory mechanisms of IS526 on rabbit articular chondrocytes were examined.Following IS526 callus extract treatment,the expression levels of differentiation-related proteins were detected via western blotting,Alcian blue staining and immune-luorescence staining.IS526 decreased the type Ⅱ collagen and proteoglycan levels in dose-and time-dependent manners.We further analyzed the effects of IS526 on skeleton genesis in zebrafish larvae using Alcian blue staining,which showed a reduction in cartilage formation along with increased production of matrix metalloproteinase(MMP)-13.IS526 also increased the phosphorylation of ERK1/2 and p38 kinase but inhibited the phosphorylation of Akt.Pharmacological inhibition of MMP-13 blocked the IS526-induced decrease in type Ⅱ collagen levels.Inhibition of p38 kinase or PI-3K/Akt with SB203580 and LY294002 enhanced the suppression of type Ⅱ collagen,but the blockage of ERK-1/2 by PD98059 rescued IS526-induced dedifferentiation.These results suggested that IS526 regulates type Ⅱ collagen and MMP-13 expression via the ERK1/2 and PI-3K/Akt pathways in rabbit articular chondrocytes.
