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Jian Lin Li Peiyu Ding Baocheng Jiang Min Yang Jie Ren Yan Song 《Natural product research》2019,33(10):1393-1398
Microbial transformation of 20(R)-panaxatriol by the fungus Aspergillus flavus Link AS 3.3950 was performed. Four new (1–4), along with two previously reported metabolites (5 and 6), were obtained. Their chemical structures were elucidated on the basis of extensive spectroscopic analyses. Furthermore, the inhibitory effects of those compounds on K562/ADR, Du-145, Hela, MCF-7 and HepG2 cell lines were evaluated by MTT assay. Among them, compound 15β-hydroxy-20(R)-panaxatriol (4) exhibited selective inhibitory effects on human leukaemic progenitor cells K562/ADR through arresting cell cycle, which was associated with obvious decrease of cyclin B1, cyclin D1 and cyclin-dependent kinase (CDK) 1/2/4/6 protein expression. 相似文献
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Meiyun Su Lina Guo Peiyu Mao Meng Xiao Prof. Dr. Wenjie Liu Prof. Dr. Shaohua Wang 《European journal of organic chemistry》2023,26(29):e202300268
The catalyst-free electrochemical halogenation and trifluoromethylation of 4H-pyrido[1,2-a]pyrimidin-4-ones was realized under external-oxidant-free conditions. This strategy provides an easy and green access to functionalized new 4H-pyrido[1,2-a]pyrimidin-4-one derivatives with broad scope, good functional group tolerance and high regioselectivity. 相似文献
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Peiyu Wang Qinglong Wang Guoheng Zhang Haiyan Jiao Xiaoyan Deng Liwei Liu 《Journal of Solid State Electrochemistry》2016,20(2):319-325
In this paper, cabbage leaves (CLs) were used to synthesize porous activated carbon by the carbonization and activation processes. The material for CLs were carbonized at 600 °C and activated at 800 °C with the KOH/C-600 mass ratio 4 (denoted as AC-800) show typical amorphous character and display porous structures with high specific surface areas 3102 m2/g via XRD and BET measurements. As the electro-active material, AC-800 electrode exhibit ideal capacitive behaviors in aqueous electrolytes and the maximal specific capacitance is as high as 336 F/g at the current density of 1 A/g. Furthermore, AC-800 electrode shows excellent electrochemical cycle stability with ~95 % initial capacitance being retained after 2000 cycles. The desirable capacitive performances enable the CLs to act as a new biomass source of carbonaceous materials for high-performance supercapacitors and low-cost electrical energy storage devices. 相似文献
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Tienhsiung Ku Peiyu Lu Chenhsiung Chan Tsusheng Wang Szuming Lai Pingchiang Lyu Naiwan Hsiao 《Computational Biology and Chemistry》2009,33(6):445-450
Proteins of both hyperthermophilic and mesophilic microorganisms generally constitute from the same 20 amino acids; however, the extent of thermal tolerance of any given protein is an inherent property of its amino acid sequence. The present study is the first to report a rapid method for predicting Tm (melting temperature), the temperature at which 50% of the protein is unfolded, directly from protein sequences (the Tm Index program is available at http://tm.life.nthu.edu.tw/). We examined 75 complete microbial genomes using the Tm Index, and the analysis clearly differentiated hyperthermophilic from mesophilic microorganisms on this global genomic basis. These results are consistent with the previous hypothesis that hyperthermophiles express a greater number of high Tm proteins compared with mesophiles. The Tm Index will be valuable for modifying existing proteins (enzymes, protein drugs and vaccines) or designing novel proteins having a desired melting temperature. 相似文献
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The lubrication layer plays a governing role in predicting the pumpability of fresh concrete. To determine the effect of measurement methods on the characterization of the rheological properties of the lubrication layer, different measurement systems, including Sliper, tribometer, and the utilization of a mortar rheometer, were employed. The rheological properties and workability of bulk concrete were measured in parallel to investigate the correlation between them and the rheological properties of the lubrication layer. The results show that the measured values of the rheological parameters of the lubrication layer differ due to the systematic deviation between different measurement methods. The results obtained by both tribometer and mortar rheometer were well-correlated, having a linear relationship with the rheological parameters of bulk concrete. The correlation coefficient between results gained with Sliper and rheological parameters of concrete or lubrication layer determined with other methods was not high enough. Addition friction led to the large accidental error and overestimated yield stress obtained with Sliper. The workability of concrete is only suitable for characterizing the rheological properties of bulk concrete. 相似文献
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以胍基取代的二甲基二氯硅烷与胺基锂反应合成了3种硅基化合物,使用核磁共振、高分辨质谱、元素分析对化合物结构进行了表征,通过热重分析(TGA)研究了化合物的热稳定性、挥发性、蒸汽压等性能。 3种化合物均具有良好的热稳定性及挥发性,无明显热分解过程,固体残留小于1%,接近纯挥发过程,最高蒸汽压在3600~5300 Pa,满足前驱体使用要求。 以二甲基-胍基-甲乙胺基-硅烷为前驱体,采用螺旋波等离子体气相沉积(HWPCVD)工艺制备了硅基薄膜,使用X射线光电子能谱(XPS)和扫描电子显微镜(SEM)分析了薄膜的化学组成和膜表面结构,XPS分析结果证实该薄膜为Si、N、C组成,实验结果表明,该类胍基硅化合物可作为硅基化学气相沉积(CVD)前驱体材料应用于集成电路制造。 相似文献