皮革涂饰用交联剂的合成及其性能研究

论述了交联对皮革涂饰的重要性 ,交联的分类以及皮革涂饰用交联剂的种类 ,重点讲述了氮丙啶交联剂的合成以及对丙烯酸树脂的交联及其性能的影响     

皮革涂饰用多功能交联剂的合成研究

本文介绍了用于乳型皮革涂饰剂的多功能交联剂的合成原理、方法以及影响合成的几个重要因素。     

皮革涂饰用交联剂的合成、作用机理、性能及发展趋势

本文系统地介绍了当皮革涂饰用交联剂的合成、作用机理及性能，并提出了皮革交联的发展方向。     

胶乳型互穿聚合物网络丙烯酸酯涂饰剂的制备及性能研究

采用乳胶型互穿聚合物网络(LIPN)技术制备了新型改性丙烯酸树脂涂饰剂。系统研究了交联剂乙二醇二丙烯酸酯的合成方法,核-壳单体组成,交联剂和乳化剂的用量及加入方式等对乳液性能的影响;对胶乳性能及胶膜物理性能进行了测试。研究表明采用LIPN技术,可以显著改善丙烯酸树脂涂饰剂的性能。     

水性聚碳化二亚胺交联剂的合成及性能研究(Ⅱ)——水性阴离子聚碳化二亚胺交联剂

以异佛尔酮二异氰酸酯(IPDI)、羟乙基磺酸钠(SHES)、3-甲基-1-苯基膦杂环戊烯-1-氧化物(MPPO)为原料,合成了水性阴离子聚碳化二亚胺交联剂。主要探讨了合成条件:亲水封端剂、封端温度及封端剂用量等因素对产物性能的影响,得出较佳的工艺条件。将成品在丙烯酸涂饰剂中应用,结果表明:成膜抗张强度由2.813MPa提高到6.147MPa;在水、0.05mol/LNaOH和乙酸丁酯中的溶胀率分别由52.3%降至26.4%、202.4%降至140.4%、843.2%降至354.8%。在丙烯酸涂饰剂中加入交联剂,涂饰后成革的耐干、湿擦性能提高。     

耐黄变溶剂型聚氨酯皮革涂饰剂的研究

通过选择脂肪族二异氰酸酯与大分子二元醇、扩链剂、交联剂合成耐黄变聚氨酯皮革涂饰剂,并对其反应温度、投料方式、固化方式对反应的影响及涂膜的耐黄变性能进行了讨论.     

有机硅改性聚氨酯树脂皮革涂饰剂SPU-01

本文介绍了端羟烷基改性聚硅氧烷改性聚氨酯树脂合成方法,并讨论了端羟烷基改性聚硅氧烷,聚丁二烯二醇,甘油三醇为交联剂,二羟甲基丙酸,异佛尔酮二异氰酸酯等原料合成的有机硅改性聚氨酯树脂作为皮革涂饰剂的性能特点。     

有机硅改性聚丙烯酸酯皮革涂饰剂的制备与表征

研究了以有机硅氧烷、丙烯酸酯为主要原料，采用乳液聚合方式合成皮革涂饰剂的方法，考察了交联剂用量、引发剂用量、反应时间、反应温度等因素对反应结果的影响。这类涂饰剂具有极好的表面性能和耐候性，成革柔软滑爽、涂层薄、强度高、真皮感强，符合现代皮革加工及应用性能要求。     

耐黄变溶剂型聚氨酯皮革涂饰剂的研究

通过选择脂肪族二异氰酸酯与大分子二元醇、扩链剂、交联剂合成耐黄变聚氨酯皮革涂饰剂，并对其反应温度、投料方式、固化方式对反应的影响及涂膜的耐黄变性能进行了讨论。     

有机硅皮革涂饰助剂的功能和作用

综述了有机硅在皮革涂饰助剂中的功能和作用,特别阐述了有机硅手感剂、光亮剂、交联剂、流平剂和消泡剂在皮革涂饰中的应用.     

山楂清除亚硝酸盐及阻断亚硝胺合成的研究

通过微波法提取山楂的活性成分,在模拟人体胃液条件下,采用分光光度法测定了不同浓度的山楂提取液对亚硝酸钠的清除能力和对亚硝胺合成的阻断能力,并与Vc进行了比较。结果表明:山楂提取液对亚硝酸钠的清除率及其对亚硝胺合成的阻断率,与其浓度基本上呈正相关,对亚硝酸钠的清除率最大可达67.53%,对亚硝胺合成的阻断率最大可达95.97%;通过与Vc的对照、分析,得出山楂提取液具有较强的清除亚硝酸钠和阻断亚硝胺合成的能力。     

氨基酸对植物乳杆菌KLDS1.0391生长及细菌素合成的影响

为探究氨基酸对植物乳杆菌生长及细菌素合成的影响，调节化学成分确定培养基中的氨基酸组成，培养植物乳杆菌KLDS1.0391，采用高效液相色谱法测定乳酸含量，通过实时聚合酶链式反应（real-time polymerase chain reaction，real-time PCR）分析细菌素和氨基酸合成相关基因的表达。结果表明，天冬氨酸、组氨酸、异亮氨酸、亮氨酸、脯氨酸、苏氨酸、酪氨酸、天冬酰胺及谷氨酰胺的缺失导致该菌生长能力和细菌素合成量均显著降低（P＜0.05）；谷氨酸、甘氨酸、丙氨酸、半胱氨酸、精氨酸、苯丙氨酸、丝氨酸、色氨酸及缬氨酸的缺失仅影响菌体生长，对细菌素合成无明显影响；而赖氨酸胁迫（缺失及过量）对菌体的生长影响很小，但却显著影响细菌素的合成。色谱结果显示，赖氨酸、酪氨酸、异亮氨酸、亮氨酸、甲硫氨酸、天冬氨酸、天冬酰胺、脯氨酸及苏氨酸单缺失后乳酸含量升高。real-time PCR结果表明，细菌素合成相关基因plnEF、plnD及plNC8HK因赖氨酸的缺失表达显著下调（P＜0.05），而上述基因在外源赖氨酸质量浓度达到2.0 g/L前，上调水平随赖氨酸添加量的增大而增大。氨基酸合成关键基因dapG、yclM 因赖氨酸缺失表达显著上调，相反，上述基因在赖氨酸质量浓度为2.0 g/L时表达量显著下调（P＜0.05）。由上述研究结果推测，当赖氨酸缺失时，菌体通过上调基因dapG 和yclM 的表达以合成多种蛋白质保证其正常生长代谢，赖氨酸可正向诱导该菌细菌素合成，其可能作为细菌素合成底物发挥作用。     

Efficient synthesis of nonnatural mutants in Escherichia coli S30 in vitro protein synthesizing system

Factors that affect the efficiency of in vitro synthesis of mutant proteins that contain nonnatural amino acids were investigated. The process of the nonnatural mutagenesis consists of chemical aminoacylation of a tRNA that contains a 4-base anticodon, followed by in vitro synthesis in the presence of an mRNA that contains the corresponding 4-base codon. Detailed studies on the time courses of the synthesis revealed two major factors that suppress the yield of nonnatural mutants compared with the wild-type protein. First, a cyclic tRNA that exists as a by-product of the chemical aminoacylation inhibits the protein synthesis. Second, the very short lifetime of a tRNA aminoacylated with a nonnatural amino acid limits the protein yield. As a simple and practical way of surmounting these factors, aminoacyl tRNA was added into the in vitro system at 5 min after the start of the synthesis. The addition increased the protein yield up to the level of conventional proteins in the in vitro system.     

黑曲霉脂肪酶在反胶束体系中的光学特性及其催化合成己酸乙酯

研究黑曲霉脂肪酶在反胶束体系中的紫外-可见吸收光谱和荧光光谱特性,并优化黑曲霉脂肪酶在反胶束中催化合成己酸乙酯的反应条件,最后分离和鉴定产物。结果表明：在反胶束体系中黑曲霉脂肪酶的结构发生了变化,芳香族氨基酸暴露更多。黑曲霉脂肪酶催化合成己酸乙酯的反应条件为：在含有异辛烷-正己醇-水的体积比为60:4:1,十六烷基三甲基溴化铵(CTAB)添加量100mmol/L的反胶束体系中,脂肪酶质量浓度为0.003g/L,己酸浓度为0.3mol/L,酸醇物质的量比为1:0.9,反应温度为35℃,摇床转速为120r/min条件下16h时己酸乙酯的合成量达到最大,己酸的转化率达到(88.92±1.00)%。     

THE INFLUENCE OF NUTRITIONAL FACTORS ON SYNTHESIS OF SALMONELLA TOXIN

The nutritional requirements for the synthesis of a cholera toxin-like toxin from Salmonella enteritidis serotype braenderup were examined. Toxin levels of both culture filtrates and sonicates were determined by the modified Chinese hamster ovary (CHO) floating cell assay. With few exceptions, most amino acids which contained charged polar R groups were stimulatory for Salmonella toxin synthesis. Glycerol enhanced toxin production to the largest extent; however, glucose was a poor carbon source suggesting that Salmonella toxin elaboration may be subject to catabolite repression. Biotin and Mn⁺⁺ were shown to increase the synthesis as well as release of this toxin. An ideal defined medium, supplemented with all the nutritional factors shown to stimulate toxin synthesis, was formulated. The amount of Salmonella toxin produced in this supplemented medium was about 82% of the total toxin elaborated when cultured in Casamino acids plus yeast extract.     

The production of ethyl acetate by soy yeast Saccharomyces rouxii NRRL Y-1096

Ethyl acetate was found to be produced in large quantities in aged cultures of the soy yeast Saccharomyces rouxii NRRL Y-1096 grown on medium containing glucose. The synthesis of ethyl acetate was investigated. The present study shows that the process of ester synthesis is essentially an aerobic one. Glucose and ethanol were the main substrates for the synthesis of ethyl acetate although to a limited extent the yeast cells were also able to synthesize the ester from ethanol alone but not from either glucose or acetate. From the results of the present study, it is suggested that the flavour-producing moromi stage of soy-sauce fermentation is necessarily a prolonged one because ethanol has first to be produced in a semi-anaerobic environment for the synthesis of the esters responsible for the characteristic bouquet and flavour of the mature soy-sauce. It should therefore be possible to shorten this stage of soy-sauce fermentation by the addition of ethanol to the moromi.     

红薯不同部位抑制亚硝化反应能力及总黄酮含量比较

测定了红薯不同部位提取物对N-亚硝胺(NDMA)合成阻断、对亚硝酸盐的清除能力及其黄酮类化合物的含量,并比较了它们之间的相关性。结果表明:在体外模拟人体胃液的条件下,红薯各部位提取物均有抑制亚硝化反应的作用,其中红薯叶对N-亚硝胺(NDMA)合成阻断及对亚硝酸盐的清除最佳,依次为红薯茎、红薯梗;其阻断和清除率随提取物浓度增加而增加;不同部位提取液对N-亚硝胺(NDMA)合成阻断作用、对亚硝酸盐的清除作用与总黄酮含量相关,相关系数分别为0.987 4、0.960 3。     

酸浓度和pH值对浓香型大曲酯化酶催化活力的影响

研究了己酸、乳酸、丁酸、乙酸的浓度以及pH值对浓香型大曲酯化酶催化合成四种酯（己酸乙酯、乳酸乙酯、丁酸乙酯、乙酸乙酯）的影响。结果表明,大曲酯化酶催化合成四种酯的最适酸质量浓度分别为己酸8 g/L,乳酸1 g/L,丁酸9 g/L,乙酸12 g/L;在同一酸浓度条件下,大曲酯化酶催化合成己酸乙酯、丁酸乙酯、乙酸乙酯最适pH值均为4.5,乳酸乙酯最适pH值为6.0;大曲酯化酶催化相同物质的量浓度混合酸的试验结果表明,己酸乙酯的合成以酯化酶催化反应为主,而乳酸乙酯和丁酸乙酯的合成以化学反应为主。     

Features of nutrition and biosynthesis of protein in animals of various ages

Age-dependent features of protein synthesis intensity were studied in tissues (liver, muscles, plasma) by the method of continuous constant L-(1-14C)-leucin infusion. The investigation was conducted in male rats aged 4 and 24 months that were bred in large and small holes, and received rations with varying protein content (2.5, 15 and 60% of casein). It has been shown that protein synthesis intensity in the tissues studied is not lowered with age, in the liver it is higher than in the muscles. Differences in the early postnatal nutrition (breeding of the animals in large and small holes) has not influenced protein synthesis in the tissues. A tendency has been observed to activation of protein synthesis in the liver with lowering protein level in the diet.