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151.
Jiaao Feng Yewei Xu Yi Sun Shangyan Wen Yonglin Lei Lin Zhang Jichuan Huo 《Journal of Polymer Research》2016,23(12):247
A series of novel poly(ether ether ketone)s containing benzimidazolone groups (PNBEEKs) with precise structures in high yields were synthesized from various stoichiometric ratio mixtures of benzimidazolone, 4,4′-dihydroxybenzophenone and 4,4′-difluorobnzophenone via a C–N/C–O coupling reaction process using sulfolane as a solvent. The reaction was carried out at 210 °C in the presence of anhydrous potassium carbonate. The structures of the resulted polymers were characterized by means of FT-IR, 1H NMR spectroscopy, 13C NMR spectroscopy, and elemental analysis, and the results were largely consistent with the proposed structure. XRD studies revealed that the incorporation of benzimidazolone groups increased the crystallinity of the resulted polymers. At the same time, as the benzimidazolone unit content in the copolymer increased, the solvent resistance properties and thermal properties of the prepared polymers improved. The polymers showed high glass transition temperatures (Tg?=?126–221 °C) and high thermal stability (Td5%?=?497–593 °C in nitrogen, 466–588 °C in air). Moreover, the resulted polymers showed good fluorescence properties and the fluorescence emission peak was 435 nm. 相似文献
152.
Greg Mann Dr. Liujie Huo Sebastian Adam Dr. Brunello Nardone Dr. Jeremie Vendome Prof. Nicholas James Westwood Prof. Rolf Müller Dr. Jesko Koehnke 《Chembiochem : a European journal of chemical biology》2016,17(23):2286-2292
The bottromycins are a family of highly modified peptide natural products, which display potent antimicrobial activity against Gram‐positive bacteria, including methicillin‐resistant Staphylococcus aureus. Bottromycins have recently been shown to be ribosomally synthesized and post‐translationally modified peptides (RiPPs). Unique amongst RiPPs, the precursor peptide BotA contains a C‐terminal “follower” sequence, rather than the canonical N‐terminal “leader” sequence. We report herein the structural and biochemical characterization of BotP, a leucyl‐aminopeptidase‐like enzyme from the bottromycin pathway. We demonstrate that BotP is responsible for the removal of the N‐terminal methionine from the precursor peptide. Determining the crystal structures of both apo BotP and BotP in complex with Mn2+ allowed us to model a BotP/substrate complex and to rationalize substrate recognition. Our data represent the first step towards targeted compound modification to unlock the full antibiotic potential of bottro‐ mycin. 相似文献
153.
Synthesis and Evaluation of Glycoconjugates Comprising N‐Acyl‐Modified Thomsen–Friedenreich Antigens as Anticancer Vaccines 下载免费PDF全文
Shuang Sun Xiu‐Jing Zheng Chang‐Xin Huo Chengcheng Song Prof. Qin Li Prof. Xin‐Shan Ye 《ChemMedChem》2016,11(10):1090-1096
Thomsen–Friedenreich (TF) antigen is an important tumor‐associated carbohydrate antigen. Its low immunogenicity, however, limits its application in the development of anticancer vaccines. To solve this problem, several N‐acyl‐modified TF derivatives were synthesized and conjugated with carrier protein CRM197 (a mutated diphtheria toxoid cross‐reactive material). The immunological results in BALB/c mice demonstrated that these modified TF antigen conjugates could stimulate the production of higher titers of IgG antibodies that cross‐reacted with native TF antigen. These glycoconjugates showed strong lymphocyte proliferative response, suggesting that they can induce cellular immunity. Furthermore, the elicited antisera reacted strongly with TF‐positive tumor cells (4T1). In particular, the N‐monofluoroacetyl‐modified TF conjugate 4 ‐CRM197 showed the strongest complement‐dependent cytotoxicity effect against 4T1 cells, implying the potential of this glycoconjugate as an anticancer vaccine. 相似文献
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155.
孙活 《沈阳工业大学学报》2017,39(5):535-539
为了解决在高速率传输过程中,光纤介质的非线性效应及其在波分复用(WDM)系统中光信号造成的严重衰减问题,围绕自相位调制和四波混频两种非线性效应进行分析,采用Opti System模拟软件分析了造成SPM和FWM效应的主要变量因素.结果表明,输入功率、信道间隔以及色散是造成自相位调制和四波混频性能变化的主要原因,通过调整这些参数可以提高光纤传输性能,为进一步优化奠定了基础. 相似文献
156.
保温措施是既有建筑节能改造中最有效的节能措施之一。在墙体节能改造设计中,保温材料种类及其厚度的确定是至关重要的,受到多个目标参数的制约和影响。基于反问题的研究方法,建立数值计算方法与多目标遗传算法NSGA-Ⅱ相结合的优化模型,以单位面积墙体全年总能耗和保温材料成本为目标参数,对成都地区某既有建筑墙体节能改造的保温材料种类与厚度进行了协同设计。结果表明,采用常规的保温厚度,常用的8种保温材料中有6种都不是最优解,但是可以通过改变保温材料的厚度或单价等方法使解向Pareto前沿逼近,以实现单位面积墙体年总能耗最小和改造成本最小之间的平衡。 相似文献
157.
Klaus-Dieter Rinnen Dahv A.V. Kliner Richard N. Zare Winifred M. Huo 《Israel journal of chemistry》1989,29(4):369-382
The relationship between quantum state populations and ion signals in (2+1) resonance-enhanced multiphoton ionization (REMPI) detection of HD is investigated both experimentally, by measurements of hot-nozzle population distributions, and theoretically, by calculations of the two-photon E,F 1Σg+—X1Σg+ transition moments. The experimental and theoretical relative rotational cross-sections are in good agreement for v″ = 0 and v″ = 1, but differ for v″ = 2 and for the relative vibrational cross-sections. Arguments are presented that saturation of the E,F-X transition is the main cause of these discrepancies. In spite of the presence of saturation, this calibration gives confidence in determining the relative internal state populations of HD from its (2+1) REMPI spectrum. 相似文献
158.
159.
厚浆环氧油舱漆以其涂层厚,干燥快,耐油防腐等优良特性,成为舰船油舱的新产品,本文介绍了该漆的研制过程,生产工艺及施工方法。 相似文献
160.