对甲苯磺酸催化合成丁酸异戊酯

对甲苯磺酸作为丁酸异戊醇的酯化催化剂,性能优于硫酸,本文探讨并确定了丁酸与异戊醇酯化反应的最佳条件:以0.2mol正丁酸为基准,醇酸摩尔比为1.5,环己烷7.5ml,催化剂用量2.5％,反应时间2小时,酯收率达94.3％。     

Protective effect of sodium butyrate on the cell culture model of Huntington disease

This study aimed to develop a cell culture model of Huntington disease and observe the effect of sodium butyrate on this cell culture model. Exon 1 of both a wild type and a mutant IT15 gene from the genomic DNA of a healthy adult and a patient with Huntington disease was amplified and cloned into the eukaryotic expression vector pEGFP-C1. Human neuroblastoma SH-SY5Y cells were transiently transfected with these recombinant plasmids in the absence and presence of sodium butyrate (0.1, 0.2, 0.5, 1.0 mmol/L). The MTT assay was used to measure cell viability. The results indicated that the N-terminal fragment of mutant huntingtin formed perinuclear and intranuclear aggregates and caused a decrease of SH-SY5Y cell viability. Sodium butyrate inhibited the decrease of SH-SY5Y cell viability caused by the N-terminal fragment of mutant huntingtin. This suggests that sodium butyrate has a protective effect on this cell culture model of Huntington disease.     

一株利用乳酸产丁酸梭菌BEY8的鉴定及其特性

从窖泥中分离到一株能利用乳酸产丁酸的菌株BEY8,基于16SrRNA基因序列分析鉴定为梭菌属(Clostridium).BEY8菌体生长和代谢乳酸的最适pH为5.5~6.0,当pH低于4.8或高于6.5,菌体均出现明显的生长和代谢延滞,但最终仍能完全将乳酸转化为丁酸;此外,当乳酸浓度达到156mM时,BEY8的生长及代谢同样出现延滞,且延滞时间随乳酸浓度的升高而延长,但最终都能完全将乳酸转化为丁酸,这些特性表明该菌有较强的环境适应能力及代谢稳定性.在pH4.8时,外加乙酸可显著缩短BEY8的生长延滞期,并提高其对乳酸的代谢速率,但乙酸不能作为菌体的唯一能源生长,而只作为电子受体参与代谢乳酸产丁酸.     

杂多酸盐异构体催化合成丁酸正戊酯

研究了以(α,β1,β2,β3-)SiW11Co为催化剂催化合成丁酸正戊酯,探讨了各种因素对产品收率的影响.实验表明,β2-SiW11Co具有较好的催化活性,以β2-SiW11Co为催化剂,适宜反应条件是醇酸比为1.8︰1,反应时间为1.5 h,催化剂用量为反应物料总量的2.3%,反应温度为125～135℃,在此条件下,产品收率为85.1%.     

固体超强酸TiO2/SO42-催化合成丁酸异丁酯

以正丁酸,异丁醇为原料,固体超强酸TiO2/SO^2- 4为催化剂,催化合成了丁酸异丁酯,考察了原料酸／醇摩尔比,温度,时间,催化剂用量和重复使用次数等工艺条件对酯化反应产率的影响,实验结果表明,在较佳工艺条件下酯产率可达88％,产品经红外表征属于高纯度的丁酸异酯酯,本合成路线具有工艺简单,无污染,催化剂可重复使用等特点。     

固体超强酸SO_4~(2-)/TiO_2催化剂及丁酸异戊酯催化酯化的研究

以工业原料制备ＳＯ２－４／ＴｉＯ２型固体超强酸催化剂，考察了制备条件对催化剂表面酸性强度酯化活性的影响，并对丁酸异戊酯的催化进行了工艺条件最优化试验，丁酸转化率可达９８％以上．     

Butyrate-induced reactivation of the fetal globin genes: A molecular treatment for theβ-hemoglobinophaties

The inherited -hemoglobinopathies (sickle cell disease and thalassemia) are the result of a mutation in the adult () globin gene. The fetal globin chain, encoded by the globin genes, can substitute for the mutated or defective globin chain, but expression of the globin gene is developmentally inactivated prior to birth. Reinducing expression of the normal fetal globin genes is a preferred method of ameliorating sickle cell disease and the thalassemias. Stimulation of as little as 4–8% fetal globin synthesis in the bone marrow can produce >20% fetal hemoglobin in the peripheral circulation, due to enhanced survival of red blood cells containing both sickle and fetal hemoglobin, compared to those containing sickle hemoglobin alone. Butyric acid and butyrate derivatives are generally safe compounds which induce fetal hemoglobin production by stimulating the promoter of the fetal globin genes. An initial trial with the parent compound, delivered as Arginine Butyrate, has demonstrated rapid stimulation of fetal globin expression to levels that have been shown to ameliorate these conditions. Phase 1 trials of an oral butyrate derivative with a long plasma half-life have just begun. These agents now provide a specific new apporach for ameliorating these classic molecular disorders and merit further investigation in larger patient populations.     

厌气反应器对基质扰乱的响应

5套 37℃的扰乱试验实施在 3台厌气完全混合反应器中。三反应器分别处理着以丙酸、丁酸和混合脂肪酸为基质的废水。扰乱由脉冲添加丙酸、丁酸或甲酸来建立。结果表示 ,扰乱立即导致了相应的酸和氢分压(pH2 )的浓度积累。但所有反应器能完全地恢复在 2 0 0h之内。混合液相中丙酸和丁酸的积累没有导致pH的重大变化。但是 ,PH2 的增加限制了丙酸和丁酸的转换 ;各自的阈值分别为 2 1× 10 - 4及 1 1× 10 - 3atm。异丁酸和二高分子羟基酸 ,valerate和caproate ,被检出存在于一些被扰乱的反应器流出水中。对于丁酸异构化pH2 的作用是非决定性的。实验数据的热力学分析表示 ,valerate和caproate的形成或归结于pH2 的增加或独立于pH2 的增加。在后者 ,形成直接地归结于混合液相中丙酸或丁酸的浓度增加。     

羟羧桥连四核钴配合物的合成和催化活性研究

作者利用丁酸钴、正丁酸和环巳酮均相体系,合成了羟羧桥连丁酸钴四核配合物.通过红外、核磁、差热热重等分析测试手段对产品进行了组成和结构的初步确定。以环巳烷为底物进行了催化性能的初步研究。     

N—丁基来酰亚胺／双环戊二烯共聚物的合成与表征

以偶氮二异丁腈为引发剂,采用溶液聚合法首次合成了NBMI-co-DCPD共聚物,用IR、DSC和TGA对共聚物进行了表征,结果表明：该共聚物具有较高的玻璃化转变温度、耐热性能良好。