51 research outputs found

    Elemene reversed the multidurg resistance of A549 /DDP lung cancer cells via mitochondrial apoptosis pathway

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    目的:探讨榄香烯乳(ElEMEnE,ElE)逆转人肺腺癌耐顺铂(CISPlATIn,ddP)细胞A549/ddP的耐药性及作用机制。方法:采用MTT法检测榄香烯乳单用的细胞毒作用及与ddP合用时耐药逆转作用。荧光探针JC-1结合激光共聚焦显微镜检测线粒体膜电位的变化。dCfH-dA荧光探针结合流式细胞仪检测细胞内活性氧(rEACTIVE OXygEn SPECIES,rOS)水平。用谷胱甘肽试剂盒结合分光光度法检测计算gSH/(gSSg+gSH)比值。蛋白质印迹法检测胞质中CyTO C、PrO-CASPASE-3、CASPASE-3和bCl-2家族蛋白表达情况。结果:不同浓度榄香烯乳抑制A549/ddP细胞株生长,呈时间-剂量依赖性效应,联合顺铂能提高A549/ddP细胞株对顺铂的敏感性而逆转耐药。不同浓度榄香烯乳联合顺铂使A549/ddP细胞株线粒体膜电位下降,rOS浓度增加,gSH/(gSSg+gSH)比值降低,上调胞质中CyTO C、CASPASE-3、bAd蛋白表达,下调PrO-CASPASE-3、bCl-2蛋白表达。结论:榄香烯乳逆转A549/ddP细胞株耐药性可能与其损伤线粒体膜,活化胞内氧化还原体系,诱导线粒体凋亡路径有关。Objective: To explore the mechanism that elemene( ELE) reversed the multidurg resistance( MDR)of A549 /DDP lung adenocarcinoma cell.Methods: MTT assay was used to determine the growth inhibition of human lung adenocarcinoma A549 /DDP cells in vitro.Mitochondrial membrane potential( MMP) was monitored by JC- 1fluorescence probe with laser confocal scanning microscopy,the intercellular reactive oxygen species( ROS) level was measured by 2',7'- dichlorfluorescein- diacetate( DCFH- DA) staining and flow cytometry and the ratio of GSH /( GSSG +GSH) was calculated according to detection results of GSH kit.The expression of Cytochrome C,Caspase-3 and the Bcl- 2 family proteins and in the case of cyclosporine A and DEVD- CHO,the expression of Caspase- 3expression were measured by Western blot.Results: MTT results showed that different concentrations ELE could inhibit the proliferation of A549 /DDP cells in a time- and dose- dependent manner.Intriguingly,ELE plus cisplatin enhanced the sensitivity of A549 /DDP cells to cisplatin and reversed A549 /DDP cells dury resistance.Different concentrations ELE decreased mitochondrial membrane potential,increased intracellular ROS concentration and decreased GSH /( GSSG + GSH) ratio of A549 /DDP cells in a time- and dose- dependent manner.Furthermore,the combination with both ELE and cisplatin also enhanced the protein expression of Cytoplasmic C,Caspase- 3 and Bad,and reduced the protein levels of Bcl- 2 and Pro- caspase- 3 in the cisplatin- resistant A549 /DDP cancer cells.Conclusion: ELE reversed the MDR of A549 /DDP cell line may demage mitochondrial membrane,active intracellular redox system and induce the mitochondrial apopotosis pathway.福建省自然科学基金面上项目(编号:2010D014

    Electrocatalytic reduction of CO2 to ethylene and ethanol through hydrogen-assisted C-C coupling over fluorine-modified copper

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    精准控制C1分子C-C偶联合成特定C2+化合物是C1化学中极具挑战性的难题。由于C2+化合物(如乙烯和乙醇)在化工和能源领域具有重要用途,将CO2直接转化为C2+产物极具吸引力。发展高效催化剂,实现高电流密度、高C2+选择性、高稳定性的“三高”性能,是推进电催化还原CO2走向实际应用的关键。研究团队针对电催化还原CO2中高CO2还原法拉第效率的催化剂常常活性低的问题,提出了适当提高催化剂活化水的能力对增加CO2还原活性的重要性,发展出氢助碳碳偶联(hydrogen-assisted C-C coupling)的新策略,在氟修饰的铜(F-Cu)催化剂上实现了CO2电催化还原制乙烯和乙醇的新突破。该研究工作实验部分主要由王野、张庆红教授指导,能源材料协同创新中心iChEM2016级博士生马文超、固体表面物理化学国家重点实验室高级工程师谢顺吉(共同第一作者)完成;理论计算部分由程俊教授指导,2017级硕士生刘彤彤(共同第一作者)、2016级博士生樊祺源完成。叶进裕博士为原位红外测试提供了支持。上海光源姜政研究员、孙凡飞博士、杨若欧为同步辐射表征提供了支持。 这是投稿的最终版本,正式出版的论文版本请访问官方链接(https://doi.org/10.1038/s41929-020-0450-0)。Electrocatalytic reduction of CO2 into multi-carbon (C2+) products is a highly attractive route for CO2 utilization. However, the yield of C2+ products remains low because of the limited C2+ selectivity at high CO2 conversion rate. Here, we report a fluorine-modified copper catalyst that exhibits an ultrahigh current density of 1.6 A cm−2 at C2+ (mainly ethylene and ethanol) Faradaic efficiency of 80% for electrocatalytic CO2 reduction in a flow cell. The C2-4 selectivity reaches 85.8% at a single-pass yield of 16.5%. We show a hydrogen-assisted C−C coupling mechanism between adsorbed formyl (CHO) intermediates for C2+ formation. Fluorine enhances water activation, CO adsorption and hydrogenation of adsorbed CO to CHO intermediate that can readily undergo coupling. Our findings offer an opportunity to design highly active and selective CO2 electroreduction catalysts with potential for practical applicationThis work was supported by the National Key Research and Development Program of the Ministry of Science and Technology of China (No. 2017YFB0602201), the National Natural Science Foundation of China (Nos. 21690082, 91545203, 21503176 and 21802110), We thank staffs at the BL14W1 beamline of the Shanghai Synchrotron Radiation Facilities (SSRF) for assistance with the EXAFS measurements.研究工作得到科技部重点研发计划(批准号:2017YFB0602201)和国家自然科学基金(批准号:21690082、91545203、21503176、21802110)项目的资助

    Identifying the Conformational Isomers of Single-Molecule Cyclohexane at Room Temperature

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    构象异构是化学中的基本问题。然而对于环己烷等柔性分子,由于其在室温下极快的互变异构过程,基于系综的表征方法(如核磁等)只能得到所有构象平均贡献的结果。为了应对这一挑战,化学化工学院洪文晶教授与夏海平教授课题组为在室温条件下对柔性分子构象的定量分析与表征这一挑战,课题组成功实现了在室温条件下对环己烷两种椅式构象的电学表征与比例识别。同时,通过纳米电极间隙对分子的限域作用,发现在宏观尺度下极不稳定的扭船式中间体得以在单分子尺度稳定存在,这为不稳定中间体的研究提供了重要表征方法。 这一研究工作是在化学化工学院洪文晶教授、夏海平教授共同指导下完成的,iChEM直博生唐淳与化工系研究生唐永翔为论文共同第一作者。师佳副教授与刘俊扬副研究员为该工作提供了指导,博士后陈志昕、博士研究生陈李珏以及研究生叶艺玲、严哲玮、张珑漪共同参与了该工作。【Abstract】Isomerism reflects the ubiquitous nature that molecules with the same molecular formula show different structures. The interconversion between conformational isomers of flexible molecules is quite fast owing to the low barriers of around 10 kcal mol−1, leading to average signal contributed by all the possible isomers characterized by ensemble methods. On this account, identifying the conformational isomers of flexible molecules at room temperature has a substantial challenge. Here, we develop a single-molecule approach to identify the conformational isomers of cyclohexane at room temperature through the single-molecule electrical characterization. By noise analysis and feature extraction of the conductance of single-molecule junctions, we quantificationally identified two chair isomers of cyclohexane at room temperature, while such identification is only feasible at low temperatures by ensemble characterization. The strategy to apply the single-molecule approach to identify conformational isomers paves the avenue to investigate the isomerization of flexible molecules beyond the ensemble methods.This work was supported by the National Natural Science Foundation of China (nos, 21722305, 21673195, 21703188, and U1705254), the National Key R&D Program of China (2017YFA0204902), China Postdoctoral Science Foundation (no. 2017M622060), and the Fundamental Research Funds for Xiamen University (20720190002).该工作获得了科技部国家重点研发计划、国家自然科学基金等项目的资助,也得到了固体表面物理化学国家重点实验室、能源材料化学协同创新中心的支持

    配位聚合物[Cu(NIPH)(bpy)]的合成、结构及性质

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    吸电子基团修饰的三苯胺星型材料,其制备方法与用途

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    本发明提供了一种新型结构的三苯胺类材料,该材料以三苯胺的星型小分子为核心,在尾端引入吸电子基团修饰,其结构通式为:其中,X结构式为R1、R2分别指代C1-C12烷基中的一种。该材料在常见的有机溶剂,如二氯甲烷、三氯甲烷、甲苯中具有良好的溶解性,可以用溶液方法制备高质量的薄膜;而且与现有聚合物材料相比更易纯化而得到高纯度材料,因此,可以作为一种新型的光电功能材料应用在光伏器件中,以解决目前光电功能材料中所存在的聚合物难于纯化,而小分子又难以溶液旋转涂膜的问题

    一种螺芴类衍生物及其制备方法和应用

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    本发明公开了一种螺芴类衍生物,其结构如式(I)所示;式(I)中,R1、R2、R3和R4为端基受体基团,独立地选自如式(I-a)、式(I-b)或式(I-c)所示的基团。该螺芴类衍生物对可见光的吸收能力强,可以作为一种小分子给体材料应用于有机太阳能领域。本发明还公开了螺芴类衍生物的制备方法,以4,7-二溴苯并噻二唑和4-己基-2-三丁基锡噻吩为起始原料,依次经过Stille偶联反应、维尔斯迈尔-哈克反应、溴代反应、Suzuki偶联反应和费纳格尔缩合反应得到螺芴类衍生物

    一种吡咯并吡咯二酮衍生物及其制备方法和应用

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    本发明公开了一种吡咯并吡咯二酮衍生物,其结构如式(I)所示;式(I)中,n=2或4;R选自如式(I-a)、式(I-b)或式(I-c)所示的基团。该吡咯并吡咯二酮衍生物对可见光的吸收能力强,可以作为一种小分子给体材料应用于有机太阳能领域。本发明还公开了吡咯并吡咯二酮衍生物的制备方法,以2-氰基噻吩和丁二酸二甲酯为起始原料,经过一系列关环、溴代和偶联反应得到所述的吡咯并吡咯二酮衍生物

    Ultrathin single crystal ZnS nanowires

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     A facile synthesis of ultrathin single crystal ZnS nanowires with an average diameter of 4.4 nm in high yield (close to 100%) was firstly reported through the pyrolysis of a single-source precursor (zinc diethyldithiocarbamate). The obtained ultrathin ZnS nanowires exhibit good optical properties and hold promise for future applications in nanodevices
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