共查询到20条相似文献,搜索用时 31 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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《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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《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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面对著名山水画家蒋贤哲先生的画作,观赏者会默默地感受到一股震撼力,它会强烈地拨动着人们的心弦,让人激动,让人陶醉,让人不忍离开,即使离去,也会回味无穷。1987年画家在上海举办画展时,画界及观众的评论,认为画家蒋贤哲先生的山水画笔墨雄健苍润,画有气势,既有深厚的传统功力,又能创新,探索多种技法,丰富画面效果,更 相似文献
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Ivan V. Gmoshinski Vladimir A. Shipelin Nikita V. Trusov Sergey A. Apryatin Kristina V. Mzhelskaya Antonina A. Shumakova Andrey N. Timonin Nikolay A. Riger Dmitry B. Nikityuk 《International journal of molecular sciences》2021,22(11)
We studied the effects of the addition of large neutral amino acids, such as tyrosine (Tyr) and tryptophan (Trp), in mice DBA/2J and tetrahybrid mice DBCB receiving a high-fat, high-carbohydrate diet (HFCD) for 65 days. The locomotor activity, anxiety, muscle tone, mass of internal organs, liver morphology, adipokines, cytokines, and biochemical indices of animals were assessed. The Tyr supplementation potentiated increased anxiety in EPM and contributed to a muscle tone increase, a decrease in the AST/ALT ratio, and an increase in protein anabolism in both mice strains. Tyr contributed to a decrease in liver fatty degeneration and ALT reduction only in DBCB that were sensitive to the development of obesity. The addition of Trp caused an increase in muscle tone and potentiated an increase in anxiety with age in animals of both genotypes. Trp had toxic effects on the livers of mice, which was manifested in increased fatty degeneration in DBCB, edema, and the appearance of micronuclei in DBA/2J. The main identified effects of Tyr on mice are considered in the light of its modulating effect on the dopamine neurotransmitter metabolism, while for the Trp supplement, effects were presumably associated with the synthesis of its toxic metabolites by representatives of the intestinal microflora. 相似文献
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Xandra Pereiro Noelia Ruzafa J. Haritz Urcola Sansar C. Sharma Elena Vecino 《International journal of molecular sciences》2020,21(23)
RNA binding protein with multiple splicing (RBPMS) is expressed exclusively in retinal ganglion cells (RGCs) in the retina and can label all RGCs in normal retinas of mice, rats, guinea pigs, rabbits, cats, and monkeys, but its function in these cells is not known. As a result of the limited knowledge regarding RBPMS, we analyzed the expression of RBPMS in the retina of different mammalian species (humans, pigs, and rats), in various stages of development (neonatal and adult) and with different levels of injury (control, hypoxia, and organotypic culture or explants). In control conditions, RBPMS was localized in the RGCs somas in the ganglion cell layer, whereas in hypoxic conditions, it was localized in the RGCs dendrites in the inner plexiform layer. Such differential distributions of RBPMS occurred in all analyzed species, and in adult and neonatal retinas. Furthermore, we demonstrate RBPMS localization in the degenerating RGCs axons in the nerve fiber layer of retinal explants. This is the first evidence regarding the possible transport of RBPMS in response to physiological damage in a mammalian retina. Therefore, RBPMS should be further investigated in relation to its role in axonal and dendritic degeneration. 相似文献
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《云南化工》2019,(9):189-194
根据环境保护部会同工业和信息化部、卫生计生委制定了《优先控制化学品名录(第一批)》共22种优先控制化学品,结合云南省化学品生产使用情况,确定云南省17种优先控制化学品生产使用。选取生产使用量较大,涉及企业较多的甲醛、萘、二氯甲烷、三氯甲烷四种优先控制化学品作为代表,重点分析这四种危险化学品的性质和常见的生产使用工艺,总结云南地区的流域分布、区域分布、行业分布及用途情况,以便于云南省优先控制化学品污染的防治,以及污染物的在优先控制化学品方面的来源解析和在环境中的迁移转化规律研究提供相应的理论支撑,为环保部门、应急部门等相关政府部门对优先控制化学品的控制和管理提供新思路。 相似文献
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Mostafa Khodakarami 《Polymer-Plastics Technology and Engineering》2017,56(18):2019-2042
Separation and purification techniques are applied in many important fields, such as in the medical, chemical, metallurgical, environmental, and pharmaceutical industries. Recent advances in separation science and the urgent need for highly selective purification have necessitated a rapid progress with respect to the reagents, chemicals, and surfactants used in separation processes to attain a high efficiency and selectivity. Polymeric materials have attracted considerable interest, and they have been widely used as extractants, catalysts, and modifiers, in separation and purification processes. This review outlines the recent advances in the use of novel polymers, natural and synthetic, in different separation and purification techniques. Various separation techniques such as chromatography, crystallization, precipitation, distillation, electrophoresis, filtration, and mineral processing methods are discussed, and the polymers used in each method are described in terms of their properties, structure, and function. The application of polymers shows great promise in achieving a highly efficient separation, especially in the areas of membrane separation and water purification. The rational design of new multifunctional polymers with triggered functions presumably presents new opportunities for the development of advanced separation methods. 相似文献
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Ozan Nazim Ciftci Roman Przybylski Magdalena Rudzińska 《European Journal of Lipid Science and Technology》2012,114(7):794-800
Composition of fatty acids, tocopherols, sterols, and TAGs in the lipids of flax, perilla, and chia seeds were investigated where lipid content was at 45, 40, and 35%, respectively. α‐Linolenic acid (ALA) dominated among fatty acids in all oils and accounted for 58.2, 60.9, and 59.8% in flax, perilla, and chia, correspondingly in these three oils trilinolenin was the main TAG found at 19.7, 22.6, and 21.3%. Triunsaturated TAGs accounted for 77.9, 77.5, and 74.5% of the total amounts in flax, perilla, and chia oils. Contents of tocopherol were at 747 in flax, 734 in perilla, and 446 mg/kg in chia seed lipids. γ‐Tocopherol was the dominating isomer contributing 72.7% in flax, 94.3% in perilla, and 94.4% in chia to the total amount of tocopherols. Flaxseed lipids contained 25.6% of plastochromanol‐8, derivative of γ‐tocotrienol with longer side chain; perilla and chia oils contained only 1.4% of it. Phytosterols were present at 4072, 4606, and 4132 mg/kg in those seeds, respectively. Among sterols, β‐sitosterol dominated and was found at 35.6, 73.3, and 49.8% of the total amounts of sterols in flax, perilla, and chia seed lipids. All of the investigated oilseeds have an excellent nutritional quality and can be a potential source of nutraceutical fats which can enrich diet in linolenic acid and other functional components. 相似文献
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Keiko Unno Yoshio Muguruma Koichi Inoue Tomokazu Konishi Kyoko Taguchi Sanae Hasegawa-Ishii Atsuyoshi Shimada Yoriyuki Nakamura 《International journal of molecular sciences》2021,22(1)
By comprehensively measuring changes in metabolites in the hippocampus of stress-loaded mice, we investigated the reasons for stress vulnerability and the effect of theanine, i.e., an abundant amino acid in tea leaves, on the metabolism. Stress sensitivity was higher in senescence-accelerated mouse prone 10 (SAMP10) mice than in normal ddY mice when these mice were loaded with stress on the basis of territorial consciousness in males. Group housing was used as the low-stress condition reference. Among the statistically altered metabolites, depression-related kynurenine and excitability-related histamine were significantly higher in SAMP10 mice than in ddY mice. In contrast, carnosine, which has antidepressant-like activity, and ornithine, which has antistress effects, were significantly lower in SAMP10 mice than in ddY mice. The ingestion of theanine, an excellent antistress amino acid, modulated the levels of kynurenine, histamine, and carnosine only in the stress-loaded SAMP10 mice and not in the group-housing mice. Depression-like behavior was suppressed in mice that had ingested theanine only under stress loading. Taken together, changes in these metabolites, such as kynurenine, histamine, carnosine, and ornithine, were suggested to be associated with the stress vulnerability and depression-like behavior of stressed SAMP10 mice. It was also shown that theanine action appears in the metabolism of mice only under stress loading. 相似文献
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Maciaszczyk-Dziubinska E Wawrzycka D Wysocki R 《International journal of molecular sciences》2012,13(3):3527-3548
Arsenic and antimony are toxic metalloids, naturally present in the environment and all organisms have developed pathways for their detoxification. The most effective metalloid tolerance systems in eukaryotes include downregulation of metalloid uptake, efflux out of the cell, and complexation with phytochelatin or glutathione followed by sequestration into the vacuole. Understanding of arsenic and antimony transport system is of high importance due to the increasing usage of arsenic-based drugs in the treatment of certain types of cancer and diseases caused by protozoan parasites as well as for the development of bio- and phytoremediation strategies for metalloid polluted areas. However, in contrast to prokaryotes, the knowledge about specific transporters of arsenic and antimony and the mechanisms of metalloid transport in eukaryotes has been very limited for a long time. Here, we review the recent advances in understanding of arsenic and antimony transport pathways in eukaryotes, including a dual role of aquaglyceroporins in uptake and efflux of metalloids, elucidation of arsenic transport mechanism by the yeast Acr3 transporter and its role in arsenic hyperaccumulation in ferns, identification of vacuolar transporters of arsenic-phytochelatin complexes in plants and forms of arsenic substrates recognized by mammalian ABC transporters. 相似文献
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Chromogranin A (CgA), B (CgB), and C (CgC), the family members of the granin glycoproteins, are associated with diabetes. These proteins are abundantly expressed in neurons, endocrine, and neuroendocrine cells. They are also present in other areas of the body. Patients with diabetic retinopathy have higher levels of CgA, CgB, and CgC in the vitreous humor. In addition, type 1 diabetic patients have high CgA and low CgB levels in the circulating blood. Plasma CgA levels are increased in patients with hypertension, coronary heart disease, and heart failure. CgA is the precursor to several functional peptides, including catestatin, vasostatin-1, vasostatin-2, pancreastatin, chromofungin, and many others. Catestatin, vasostain-1, and vasostatin-2 suppress the expression of vascular cell adhesion molecule-1 and intercellular adhesion molecule-1 in human vascular endothelial cells. Catestatin and vasostatin-1 suppress oxidized low-density lipoprotein-induced foam cell formation in human macrophages. Catestatin and vasostatin-2, but not vasostatin-1, suppress the proliferation and these three peptides suppress the migration in human vascular smooth muscles. Chronic infusion of catestatin, vasostatin-1, or vasostatin-2 suppresses the development of atherosclerosis of the aorta in apolipoprotein E-deficient mice. Catestatin, vasostatin-1, vasostatin-2, and chromofungin protect ischemia/reperfusion-induced myocardial dysfunction in rats. Since pancreastatin inhibits insulin secretion from pancreatic β-cells, and regulates glucose metabolism in liver and adipose tissues, pancreastatin inhibitor peptide-8 (PSTi8) improves insulin resistance and glucose homeostasis. Catestatin stimulates therapeutic angiogenesis in the mouse hind limb ischemia model. Gene therapy with secretoneurin, a CgC-derived peptide, stimulates postischemic neovascularization in apolipoprotein E-deficient mice and streptozotocin-induced diabetic mice, and improves diabetic neuropathy in db/db mice. Therefore, CgA is a biomarker for atherosclerosis, diabetes, hypertension, and coronary heart disease. CgA- and CgC--derived polypeptides provide the therapeutic target for atherosclerosis and ischemia-induced tissue damages. PSTi8 is useful in the treatment of diabetes. 相似文献
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Robbe Naert Alejandro Lpez-Requena Karel Talavera 《International journal of molecular sciences》2021,22(21)
The non-selective cation channel TRPA1 is best known as a broadly-tuned sensor expressed in nociceptive neurons, where it plays key functions in chemo-, thermo-, and mechano-sensing. However, in this review we illustrate how this channel is expressed also in cells of the immune system. TRPA1 has been detected, mainly with biochemical techniques, in eosinophils, mast cells, macrophages, dendritic cells, T cells, and B cells, but not in neutrophils. Functional measurements, in contrast, remain very scarce. No studies have been reported in basophils and NK cells. TRPA1 in immune cells has been linked to arthritis (neutrophils), anaphylaxis and atopic dermatitis (mast cells), atherosclerosis, renal injury, cardiac hypertrophy and inflammatory bowel disease (macrophages), and colitis (T cells). The contribution of TRPA1 to immunity is dual: as detector of cell stress, tissue injury, and exogenous noxious stimuli it leads to defensive responses, but in conditions of aberrant regulation it contributes to the exacerbation of inflammatory conditions. Future studies should aim at characterizing the functional properties of TRPA1 in immune cells, an essential step in understanding its roles in inflammation and its potential as therapeutic target. 相似文献
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Sandhoff disease (SD) is a glycosphingolipid (GSL) storage disease that arises from an autosomal recessive mutation in the
gene for the β-subunit of β-Hexosaminidase A (Hexb gene), which catabolizes ganglioside GM2 within lysosomes. Accumulation of GM2 and asialo-GM2 (GA2) occurs primarily in the
CNS, leading to neurodegeneration and brain dysfunction. We analyzed the total lipids in the brains of SD mice, cats, and
humans. GM2 and GA2 were mostly undetectable in the normal mouse, cat, and human brain. The lipid abnormalities in the SD
cat brain were generally intermediate to those observed in the SD mouse and the SD human brains. GM2 comprised 38, 67, and
87% of the total brain ganglioside distribution in the SD mice, cats, and humans, respectively. The ratio of GA2–GM2 was 0.93,
0.13, and 0.27 in the SD mice, cats, and humans, respectively, suggesting that the relative storage of GA2 is greater in the
SD mouse than in the SD cat or human. Finally, the myelin-enriched lipids, cerebrosides and sulfatides, were significantly
lower in the SD brains than in the control brains. This study is the first comparative analysis of brain lipids in mice, cats,
and humans with SD and will be important for designing therapies for Sandhoff disease patients. 相似文献