共查询到20条相似文献,搜索用时 234 毫秒
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沈英 《精细化工原料及中间体》2014,(3)
正本发明涉及一种氢溴酸普拉格雷醋酸化合物的合成方法。以普拉格雷为中间体,将普拉格雷和水混合搅拌,得悬浊液,然后与氢溴酸和醋酸反应,加入有机溶剂,析出固体,干燥,即得,或者,以氢溴酸普拉格雷为中间体,将氢溴酸普拉格雷和水混合搅拌,得悬浊液,然后和醋酸反应,加入有机溶剂,析出固体,干燥,即得。本发明采用水作为溶剂,更加环保,节能,而且本发明步骤简单,得到的产物纯度高,生产成本低,可工业化生产。公开号:CN103450219A 相似文献
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晚清以来碑学大兴,大篆名家辈出,吴昌硕结体长方,左低右高,取斜势,陶博吾书自石鼓,自得天成,放逸随意,破石鼓文之匀雅,变而奇崛峭拔。大篆取向多样,吸引着学人为之研究,近人罗振玉、丁辅之、董作宾诸人均在此处取得了可贵的成就,张云龙先生所书的大篆有独到之处,《石鼓文》之外,兼擅《散氏盘》、《毛公鼎》、琅邪刻石等,于秦砖汉瓦自有天机处,别开新境。大篆是以形为上,云龙先生取钟鼎之浑圆,玉筋之婉通,或取诏版之方折,不拘泥于原形勾画。其大篆的线条自成一相,方圆错落有致,章法布白高妙,静中有动,动中有静,字距参差有致,行距疏宕有韵,别具生机。 相似文献
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改革开放以来,我国橡胶工业的发展速度是前所未有的,其间有许多成功的经验,特别是入世后,在上世纪末全行业整体亏损的不利情况下,大家认识一致,认真对待,风雨同舟,趋利避害,经受住了考验,不仅行业经济全面复苏,而且取得新的发展。当前,全行业面对的是新一轮的竞争,而且更为激烈 相似文献
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以硫酸氢钠为催化剂,乙酸与乙醇为原料合成了乙酸乙酯,讨论了酸醇物质的量比、催化剂用量、反应时间、带水剂等因素对酯化率的影响,确定了最佳工艺条件为:以0.2mol乙醇为基准,酸醇物质的量比为1.5∶1,催化剂用量为1.5g,反应时间为2h,带水剂环己烷为10mL,乙酸乙酯的酯化率为85.2%.该催化剂具有催化效果好,使用量少,酯化率高,能够重复使用,环境污染小,腐蚀性小,价格低廉易得等特点,是一种很有发展前景的催化剂. 相似文献
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《中国耐火材料》2015,(1):72-74
<正>Sinosteel Luoyang Institute of Refractories Research Co.,Ltd.(LIRR)is a science and technology enterprise affiliated to Sinosteel Corporation,China.LIRR,established in 1963,is the only large integrated research institute and the center of technology,science,information and services in refractories industry.Its business scope covers refractory products,testing equipment,processing tools,project design,consultation and turnkey,domestic and foreign trade,products quality inspection,information service,etc. 相似文献
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《聚氨酯》2014,(7)
<正>一、市场行情简述本月行情:本月AA市场窄幅整理,月初,海力公布挂牌,受到上游原料纯苯强势走势影响,上调500元/吨,对外执行11,500元/吨,贸易商心态得到提振,纷纷上调报盘,刺激下游接货,但端午节后归市下游惯性观望,交投有限,中旬时期,随着下游进入传统行业淡季,需求明显萎缩,贸易商报盘坚挺,但实则成交重心暗降,随着明稳暗降操作,场内低价货源陆续增多,下游采购谨慎,临近月末,上游原料纯苯挂牌上调300元/吨,强势震荡影响市场操作积极性,海力又公布了6月结算价格,对外执行11,500元/吨,提振持货商心态,但实盘成交寥寥,下游需求跟进滞缓。上游原料: 相似文献
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硫磺别名硫、胶体硫、硫黄块,外观为淡黄色脆性结晶或粉末,有特殊臭味.分子量为32.06,蒸汽压是0.13 kPa,闪点为207℃,熔点为119℃,沸点为444.6℃,比重、熔点及其在二硫化碳中的溶解度均因晶体不同而异,工业硫磺呈黄色或淡黄色,有块状、粉状、粒状或片状等.块状硫磺为淡黄色块状结晶体,粉末为淡黄色粉末,能溶于二硫化碳、四氯化碳和苯,不溶于水. 相似文献
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Dr. Alexandra Julier Dr. Vanessa Radtke Prof. Dr. Andreas Marx Prof. Dr. Martin Scheffner 《Chembiochem : a European journal of chemical biology》2022,23(6):e202100659
The tumor suppressor p53 is regulated by various posttranslational modifications including different types of ubiquitylation, which exert distinct effects on p53. While modification by ubiquitin chains targets p53 for degradation, attachment of single ubiquitin moieties (mono-ubiquitylation) affects the intracellular location of p53 and/or its interaction with chromatin. However, how this is achieved at the molecular level remains largely unknown. Similarly, since p53 can be ubiquitylated at different lysine residues, it remains unclear if the eventual effect depends on the position of the lysine modified. Here, we combined genetic code expansion with oxime ligation to generate p53 site-specifically mono-ubiquitylated at position 120. We found that mono-ubiquitylation at this position neither interferes with p53 ubiquitylation by the E3 ligases HDM2 and E6AP in complex with the viral E6 oncoprotein nor affects p53 binding to a cognate DNA sequence. Thus, ubiquitylation per se does not affect physiologically relevant properties of p53. 相似文献
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R. N. Gedye Y. N. Sadana A. C. E. Edmonds M. L. Langlois 《Journal of Applied Electrochemistry》1987,17(4):731-736
Electrolysis of nitration waste sulphuric acid, from the manufacture of trinitrotoluene, results in the formation of a dark solution in which the concentration of aromatics is reduced to much lower levels. The resulting acid can be decolourized by oxidation with H2O2 or by anodic oxidation in the cell. The H2O2-treated electrolysed acid has a nitroaromatic content of 107 p.p.m. and a total carbon content of 278 p.p.m., corresponding to a reduction of 98.7% and 90.3%, respectively. The dark intermediate product appears to result from the anodic oxidation of amines which are initially produced at the cathode, and is destroyed by further anodic oxidation on prolonged electrolysis. 相似文献
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Titanium diboride, vacuum sintered in a graphite furnace, can develop a thin TiC surface layer. A mechanism for carbide formation is proposed which takes into account the changing p(CO2 )/p(CO) ratio as a function of temperature. At low temperature, TiB2 is oxidized by CO2 to give a surface oxide layer. As the temperature is increased, the reduced p(CO2 )/p(CO) ratio allows formation of TiC via a reaction between the oxide layer and CO. The proposed mechanism is supported by thermochemical calculation and microstructural analysis. 相似文献
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Inhibition of p53 deSUMOylation Exacerbates Puromycin Aminonucleoside-Induced Apoptosis in Podocytes
Lingyu Wang Jingwei Zhu Ming Fang Tuaner Zhang Hua Xie Nan Wang Nan Shen Hui Guo Bo Fu Hongli Lin 《International journal of molecular sciences》2014,15(11):21314-21330
Apoptosis is a major cause of reduced podocyte numbers, which leads to proteinuria and/or glomerulosclerosis. Emerging evidence has indicated that deSUMOylation, a dynamic post-translational modification that reverses SUMOylation, is involved in the apoptosis of Burkitt’s lymphoma cells and cardiomyocytes; however, the impact of deSUMOylation on podocyte apoptosis remains unexplored. The p53 protein plays a major role in the pathogenesis of podocyte apoptosis, and p53 can be SUMOylated. Therefore, in the present study, we evaluated the effect of p53 deSUMOylation, which is regulated by sentrin/SUMO-specific protease 1 (SENP1), on podocyte apoptosis. Our results showed that SENP1 deficiency significantly increases puromycin aminonucleoside (PAN)-induced podocyte apoptosis. Moreover, SENP1 knockdown results in the accumulation of SUMOylated p53 protein and the increased expression of the p53 target pro-apoptotic genes, BAX, Noxa and PUMA, in podocytes during PAN stimulation. Thus, SENP1 may be essential for preventing podocyte apoptosis, at least partly through regulating the functions of p53 protein via deSUMOylation. The regulation of deSUMOylation may provide a novel strategy for the treatment of glomerular disorders that involve podocyte apoptosis. 相似文献
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Kinetics of Vapor-Phase Hydration of Magnesium Oxide 总被引:1,自引:0,他引:1
Magnesium oxide prepared by calcining the carbonate at 1000°C was sintered at 1800°C and ground under methanol. Well-sized 2 to 5 and 5 to 10 μ fractions were separated. After outgassing at 550°C in vacuum, the powders were hydrated at various temperatures to 98°C in a wide range of water vapor pressures, and the reaction was followed gravimetrically with a silica helix balance. At low temperatures and vapor pressures, where nucleation is exceedingly slow, the hydration of prenucleated samples was studied. The results are interpreted on the basis of a model in which an interface reaction controls the progress of the reaction. The reaction rate varies with the water vapor pressure p according to a function ( p / p * - 1), where p 0.3 p sat. and appears to correspond to the equilibrium adsorption pressure. This suggests that the reaction depends on an adsorbed water vapor film which has free access to the reacting surface. The reaction rate constant varies with temperature according to an Arrhenius-type equation, with an activation energy 16,100 cal per mole. 相似文献