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聚酯型聚硫醇固化剂的活性持久性的研究 被引量:1
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作者 廖毅彬 殷瑜 +6 位作者 寇亮亮 林德洵 林彩凤 陆嘉 薛惠芸 郑津 邹友思 《厦门大学学报(自然科学版)》 CAS CSCD 北大核心 2014年第4期525-530,共6页
对比了聚醚型聚硫醇和2种聚酯型聚硫醇的活性寿命的差异.通过红外光谱、1 H-NMR和凝胶时间的测试表征聚硫醇的活性寿命.结果表明,以叔胺为促进剂时,以β-巯基丙酸为原料制备得到的聚酯型聚硫醇P(SH)6和聚醚型聚硫醇P(SH)3固化剂都有良... 对比了聚醚型聚硫醇和2种聚酯型聚硫醇的活性寿命的差异.通过红外光谱、1 H-NMR和凝胶时间的测试表征聚硫醇的活性寿命.结果表明,以叔胺为促进剂时,以β-巯基丙酸为原料制备得到的聚酯型聚硫醇P(SH)6和聚醚型聚硫醇P(SH)3固化剂都有良好的活性寿命;而以α-巯基乙酸为原料制备得到的聚酯型聚硫醇P(SH)4固化剂存在活性下降的问题,2个月后完全失活.通过红外光谱、1 H-NMR表征活性下降前后其基团的变化提出了可能导致其活性下降的机理及解决的方法. 展开更多
关键词 聚酯型聚硫醇 聚醚型聚硫醇 季戊四醇巯基乙酸酯 活性寿命
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Na/HMPA溶剂化电子引发MMA的聚合行为
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作者 李智 鲁潇 +3 位作者 沈政 夏逸尘 许平 黄健 《南京工业大学学报(自然科学版)》 CAS 北大核心 2019年第1期36-40,共5页
以Na/六甲基磷酰三胺(HMPA)的溶剂化电子溶液引发甲基丙烯酸甲酯(MMA)的聚合,研究聚合动力学及阻聚性质,采用傅里叶变换红外光谱(FT-IR)和核磁共振(NMR)方法表征聚合物的分子量和化学结构。结果表明:溶剂化电子引发MMA聚合的活性种具有... 以Na/六甲基磷酰三胺(HMPA)的溶剂化电子溶液引发甲基丙烯酸甲酯(MMA)的聚合,研究聚合动力学及阻聚性质,采用傅里叶变换红外光谱(FT-IR)和核磁共振(NMR)方法表征聚合物的分子量和化学结构。结果表明:溶剂化电子引发MMA聚合的活性种具有长寿命性质。得到的聚甲基丙烯酸甲酯(PMMA)为无规结构,其全同、无规和间同结构的占比分别为10. 2%、41. 0%和48. 8%。1,1-二苯基-2-三硝基苯肼(DPPH)和O_2是强烈的阻聚剂,而H_2O不具有阻聚性能,排除了溶剂化电子引发MMA聚合的阴离子聚合机制。 展开更多
关键词 溶剂化电子 NA 六甲基磷酰三胺 聚甲基丙烯酸甲酯 寿命活性
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The MNS16A polymorphism in the TERT gene in peri-centenarians from the Han Chinese population 被引量:1
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作者 LIU LiNa WANG ChengYe +5 位作者 LU Xiang XIAO FuHui WANG HuaWei YANG LiQin XU LiangYou KONG QingPeng 《Science China(Life Sciences)》 SCIE CAS 2014年第10期1024-1027,共4页
MNS16A, a variable number of tandem repeats polymorphism in the TERT gene, has been suggested to regulate telomerase activity. As telomerase activity has been reported to be related to life-span, we hypothesized that ... MNS16A, a variable number of tandem repeats polymorphism in the TERT gene, has been suggested to regulate telomerase activity. As telomerase activity has been reported to be related to life-span, we hypothesized that this polymorphism might affect human longevity by controlling the length of the telomere. To test this hypothesis, we collected 446 unrelated pericentenarian individuals (age)90, mean 94.45±3.45 years) and 332 normal controls (age 22-53, mean 35.0±12.0 years) from Dujiangyan, Sichuan, China. We typed the MNS16A polymorphism in both groups, and compared the allele and genotype frequencies between the peri-centenarian and control groups using the chi-squared test. There was no significant difference between the peri-centenarian and control groups. Thus, the MNS16A polymorphism in TERT might not influence human life-span, at least in the Hart Chinese population studied here. 展开更多
关键词 TELOMERASE LONGEVITY MNS16A polymorphism peri-centenarian
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Artemisinin mimics calorie restriction to extend yeast lifespan via a dual-phase mode: a conclusion drawn from global transcriptome profiling 被引量:6
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作者 WANG DaTing WU Ming +2 位作者 LI SiMing GAO Qian ZENG QingPing 《Science China(Life Sciences)》 SCIE CAS CSCD 2015年第5期451-465,共15页
Calorie restriction(CR) promotes longevity among distinct organisms from yeast to mammals. Although CR-prolonged lifespan is believed to associate with enhanced respiratory activity, it is apparently controversial for... Calorie restriction(CR) promotes longevity among distinct organisms from yeast to mammals. Although CR-prolonged lifespan is believed to associate with enhanced respiratory activity, it is apparently controversial for accelerated energy consumption regardless of insufficient nutrient intake. In reconciling the contradiction of less food supply versus much metabolite dispense, we revealed a CR-based mode of dual-phase responses that encompass a phase of mitochondrial enhancement(ME) and a phase of post-mitochondrial enhancement(PME), which can be distinguished by the expression patterns and activity dynamics of mitochondrial signatures. ME is characterized by global antioxidative activation, and PME is denoted by systemic metabolic modulation. CR-mediated aging-delaying effects are replicated by artesunate, a semi-synthetic derivative of the antimalarial artemisinin that can alkylate heme-containing proteins, suggesting artesunate-heme conjugation functionally resembles nitric oxide-heme interaction. A correlation of artesunate-heme conjugation with cytochrome c oxidase activation has been established from adduct formation and activity alteration. Exogenous hydrogen peroxide also mimics CR to trigger antioxidant responses, affect signaling cascades, and alter respiratory rhythms, implying hydrogen peroxide is engaged in lifespan extension. Conclusively, artesunate mimics CR-triggered nitric oxide and hydrogen peroxide to induce antioxidative networks for scavenging reactive oxygen species and mitigating oxidative stress, thereby directing metabolic conversion from anabolism to catabolism, maintaining essential metabolic functionality, and extending life expectancy in yeast. 展开更多
关键词 calorie restriction nitric oxide ARTESUNATE hydrogen peroxide LONGEVITY Saccharomyces cerevisiae
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