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吸热型碳氢燃料裂解引发剂筛选及引发机理分析 总被引:1,自引:1,他引:0
筛选可溶性添加剂替代多相催化剂, 达到促进吸热型碳氢燃料裂解、提高燃料热沉以及燃烧性能的目的. 采用考察裂解气相产物气体流量的方法进行实验. 测试了10种添加剂在500~650 ℃范围内对正庚烷裂解效果的影响. 研究发现, 三乙胺、2,6-二叔丁基对甲酚(BHT)可促进正庚烷裂解, 其它添加剂均无显著效果. 在550 ℃时, 当三乙胺质量分数达到6%时, 实验总气体收率比计算总气体收率增加80%以上. 机理研究表明, 三乙胺的引发剂基团来源于C—N键的断裂. BHT的结构、性状与前者显著不同, 在550 ℃时, 当BHT质量分数为3.4%时体系的气体收率较之纯正庚烷裂解气体收率增加80%以上, BHT的引发基团主要是连接于叔丁基上的甲基发生脱离的结果 相似文献
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根据p53基因的序列设计并合成了能特异性检测p53 mRNA的分子信标(MB), 发展了一种快速定量测定细胞内总RNA提取物中p53 mRNA的方法. 采用鼻咽癌(CNE2)细胞系和经RNA干扰技术降低p53基因表达的CNE2-p53RNAi细胞系, 抽提总RNA并用MB检测, 验证了MB的检测对象是p53 mRNA. 将该方法应用于多种肿瘤细胞内p53基因表达水平的分析, 表达变化趋势与经典的mRNA分析方法RT-PCR检测结果相符. 在此基础上, 用MB对5-氟尿嘧啶(5-Fu)处理的肺腺癌细胞(A549)进行了p53 mRNA的体外定量检测, 结果表明采用MB能够快速地获知该药物对细胞内p53 mRNA表达影响的信息. 相似文献
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Morris SM Pipkin JL Hinson WG Shaddock JG Tolleson WH Young JF Casciano DA 《Electrophoresis》2001,22(10):2092-2097
In a previous study, the strength of the interaction between the nuclear stress proteins (sps) 25a, 70i, 72c, and 90 and the tumor suppressor protein p53 was determined by an in vitro fluorescence binding assay. The relative binding of the individual sps with p53, derived from the bone marrow of transgenic mice heterozygous at the p53 locus (p53+/-), was reduced compared to the interaction of sps and p53 derived from wild-type (p53+/+) mice. In order to determine if the genotype of the p53 donor or the genotype of the sp donor determined the binding efficiency, p53 expression was induced by retinoic acid and sp synthesis by bleomycin. P53 derived from either wild-type or heterozygous animals was cross-reacted with nuclear sps obtained from either wild-type or heterozygous animals. Each of the sps, 25a, 70i, 72c, and 90, bound to wild-type p53 with a similar efficiency, irrespective of the genotype of the sp donor mouse (p53+/+ or p53+/-). In contrast, when the sp interaction with p53 obtained from the heterozygous mouse was measured, the relative value of the fluorescence complex was significantly reduced. The data suggest that the strength of the interaction between p53 and nuclear sps is related to the genotype of the p53 donor, and not to the genotype of the animals from which the sps are derived. 相似文献
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A radiochemical method was developed to separate the group of the noble metals simultaneously from a lead matrix after irradiation with thermal neutrons. The resulting complex γ-spectrum was resolved by matrix calculus. Smoothing of the obtained data to determine the presence of small photopeaks among the background fluctuations, was done by convolution, based on a least squares approximation. The interference of antimony and bromine was studied. Amounts as low as 20–30 p.p.b. of Hg and less than 1 p.p.b. of Au were determined in the presence of up to 9 p.p.m. of Ag. 相似文献
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In this study, the aged dermal fibroblast model was constructed by repeated irradiation with UV light and the effect of lupeol, a triterpenoid, on anti‐aging was confirmed. SA‐β‐galactosidase (SA‐β‐gal) stained aged cells increased by about 40% and expression of p‐p53, p21, p16 and MMPs (MMP‐1, ‐2, ‐3) increased in aged fibroblast. As an efficacy result, the treatment of lupeol on aged fibroblast induced by UVA repeated irradiation showed a dose‐dependent reduction of SA‐β‐gal stained aged cells, the expression of p‐p53, p21, p16 and inhibition of MMPs. Interestingly, lupeol increased dephosphorylation of p‐ERK in repeated UV irradiated conditions. Additionally, lupeol compensated MMPs expression when p‐ERK phosphorylation was inhibited by p‐ERK inhibitor PD98059. Thus, these results showed that lupeol has a possible effect on MMPs expression using inhibition of the p‐ERK pathway. Taken together, we confirmed that lupeol inhibits senescence through inhibiting MMP‐1, ‐2, ‐3 as well as p‐p53, p21 and p16 expression and SA‐β‐gal activity in repeated UVA‐irradiated senescent FB models, therefore suggesting that lupeol may be useful as an anti‐aging agent. 相似文献
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SC-560, a structural analogue of celecoxib, induces growth inhibition in a wide range of human cancer cells in a cyclooxygenase (COX)-independent manner. Since SC-560 suppresses the growth of cancer cells mainly by inducing cell cycle arrest, we sought to examine the role of p21CIP1, a cell cycle regulator protein, in the cellular response against SC-560 by using p21(+/+) and p21(-/-) isogenic HCT116 colon carcinoma cells. In HCT116 (p21(+/+)) cells, SC-560 dose-dependently induced growth inhibition and cell cycle arrest at the G1 phase without significant apoptosis induction. SC-560-induced cell cycle arrest was accompanied by upregulation of p21CIP1. However, the extent of SC-560-induced accumulation at the G1 phase was approximately equal in the p21(+/+) and the p21(-/-) cells. Nonetheless, the growth inhibition by SC-560 was increased in p21(-/-) cells than p21(+/+)cells. SC-560-induced reactive oxygen species (ROS) generation did not differ between p21(+/+) and p21(-/-) cells but the subsequent activation of apoptotic caspase cascade was more pronounced in p21(-/-) cells compared with p21(+/+) cells. These results suggest that p21CIP1 blocks the SC-560-induced apoptotic response of HCT116 cells. SC-560 combined with other therapy that can block p21 CIP1 expression or function may contribute to the effective treatment of colon cancer. 相似文献
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Hideyuki Higashimura Kiyoshi Fujisawa Masaaki Kubota Shiro Kobayashi 《Journal of polymer science. Part A, Polymer chemistry》2005,43(9):1955-1962
“Radical‐controlled” oxidative polymerization of phenol (p‐1) by (1,4,7‐triisopropyl‐1,4,7‐triazacyclononane)copper(II) catalyst was performed and compared with that of 4‐phenoxyphenol (p‐2) in detail. Although the coupling selectivity for p‐1 seemed to be controlled by the catalyst, the C? C coupling, which was excluded completely for p‐2, occurred to some extent. The initial reaction rate of p‐1 was much smaller than that of p‐2, leading to the difference of polymerization behavior between p‐1 and p‐2. The rate‐determining step would be the coupling of controlled radicals species from the ESR measurement of the reaction mixture. The polymer resulting from p‐1 consisted mainly of phenylene oxide units, but had no crystallinity in contrast to the crystalline polymer from p‐2. However, the present polymer showed the highest thermal stability in the polymers obtained by oxidative polymerization of p‐1. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1955–1962, 2005 相似文献
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Urine samples were digested with a mixture of nitric, sulfuric, and perchloric acids containing molybdate as catalyst. A two-point standard addition technique involved extracts of buffered, digested aliquots containing 10- and 20-p.p.b. manganese(II) in the aqueous phase. The extraction system was MIBK-cupferron. Of the substances tested only bismuth, antimony, and thallium interfered. From the same subject, five morning urine samples averaged 3.0 p.p.b. of manganese with a range of 2.0–4.2 p.p.b.; the average deviation was 0.6 p.p.b. 相似文献