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降解壳聚糖季铵盐是将降解壳聚糖的氨基通过引入基团转换成季铵盐或者把一个低分子季铵盐接到氨基上而得到的一类降解壳聚糖衍生物。降解壳聚糖季铵盐在亚麻织物染色中的应用研究表明其具有一定的助染作用。国外对壳聚糖季铵盐的合成已有报道,如1985年国外报道了碘化壳聚糖季铵盐的合成方法,但得到的碘化N-三甲基壳聚糖季铵盐是不溶于水的。 相似文献
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壳聚糖季铵盐及其衍生物的应用研究进展 总被引:1,自引:0,他引:1
壳聚糖是一种天然无毒多糖,可生物降解,具有生物相容性。在实际应用中壳聚糖水溶性差,只能在酸性介质中溶解。为了提高壳聚糖的溶解度并改善其理化及生物特性以扩大其应用范围,有必要对壳聚糖进行化学修饰。壳聚糖季铵盐是一种常见的壳聚糖修饰产物,属于水溶性壳聚糖衍生物,由于骨架上有强正电荷,因此其pH值溶解范围较宽。综述了壳聚糖季铵盐及其衍生物在抗菌活性、基因运载、给药系统、抗凝血材料、传感器等方面的应用进展,提出改进壳聚糖季铵盐及其衍生物的合成路线,可合成一系列生物学性能改良的壳聚糖季铵盐及其衍生物,有望将其应用于特殊领域。 相似文献
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用2,3-环氧丙基三甲基氯化铵对壳聚糖进行改性得到壳聚糖季铵盐,进一步通过乳化交联法合成壳聚糖季铵盐微球,采用傅里叶变换红外光谱(FT-IR)、差热热重分析(TG-DTG)、X-衍射衍射(XRD)和扫描电镜(SEM)对其进行表征分析。此外,研究了壳聚糖季铵盐的浓度、油水比、交联剂用量对合成的壳聚糖季铵盐微球吸附Cr(Ⅵ)性能的影响,并考察了重铬酸钾初始浓度、pH值、壳聚糖季铵盐微球添加量对Cr(Ⅵ)吸附效果的影响。结果表明:HACC浓度为0.8%(w/V)、油水比为8∶1、壳聚糖季铵盐与交联剂质量比为1.64的条件下,可以制备出球型圆整、分散性好的壳聚糖季铵盐微球。在酸性条件和较低浓度的重铬酸钾均有利于壳聚糖季铵盐微球对Cr(Ⅵ)的吸附。 相似文献
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壳聚糖季铵盐的合成及其对鞣酸的絮凝性能 总被引:3,自引:0,他引:3
通过引入季铵盐基团的方法对壳聚糖进行改性得到完全溶于水的壳聚糖季铵盐,IR谱图表明取代反应主要发生在壳聚糖的氨基上。以中药药液中的主要杂质之一鞣酸为对象进行了絮凝试验,结果显示其鞣酸去除率,明显高于壳聚糖。同时壳聚糖季铵盐絮凝剂投加量适用范围更宽,有利于实际使用。 相似文献
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亚硝化反硝化聚磷菌(NDPAOs)以亚硝酸盐为电子受体,具有同时脱氮除磷的特点,能够最大程度地减少碳源和氧气需求,因此可以大大减少能耗,节约成本。试验研究了7种NDPAOs——肠杆菌属(Ent.)、葡萄球菌属(Sta.)、副球菌属(Par.)、泛菌属(Pan.)、克雷伯氏菌属(Kle.)、芽孢杆菌属(Bac.)和莫拉氏菌属(Mor.)的释磷特性,并以纯培养的方式研究了它们的生长特性。结果表明,缺氧反应20 h后,Sta.、Bac.、Par.、Kle.、Pan.、Ent.和Mor.的单位细胞吸磷量分别为1.98×10-11、1.64×10-11、1.43×10-11、1.13×10-11、9.59×10-12、7.72×10-12和6.28×10-12mg/cfu。Ent.、Kle.、Bac.、Pan.、Par.、Sta.和Mor.的缓慢期几乎都处于0~6 h之间,对数期分别为6~144、6~72、6~96、6~52、6~31、6~96和6~72 h。Par.、Sta.、Pan.和Mor.的对数期的生长速率较Ent.、Bac.和Kle.的小。不同菌属的亚硝化反硝化聚磷菌的生长特性也不完全相同,特别是对数期的生长速率以及维持的时间相差较大。 相似文献
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研究了贵州湄潭产苦丁茶挥发油的化学成分。用水蒸气蒸馏提取贵州苦丁茶挥发油,用GC-MS分析和鉴定出化学成分,使用峰面积归一法确定其百分含量。结果表明:挥发性成分的得率分别为0.17%。从苦丁茶挥发油中鉴定出13种(占挥发油总量的81.64%)化合物,苦丁茶挥发油的主要成分是β-芳樟醇、β-月桂烯、α-松油醇、(Z)-柠檬醛、(E)橙花醇。不同地区的苦丁茶挥发油的主要成分和含量差异差较大,在其饮品开发利用中都应区别对待。 相似文献
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The light-induced degradation of lignin was studied using spruce MWL impregnated on handsheets prepared from cotton linters. The sheets were irradiated with simulated sunlight and the lignin was extracted. Solutions of untreated and irradiated lignin were studied by 1H and 13C NMR spectroscopy. The results showed that α- and β- ether and α-β bond cleavage were the main reactions. The main degradation products were vanillin and vanillic acid. The amount of terminal groups containing aromatic aldehyde and carboxyl groups also incre- ased on irradiation. The existing α- C=O groups were transformed mainly to carboxyl groups. However, the results indicate that new α- C=O groups were generated on irradiation. The methoxyl content decreased and some degradation of aromatic rings took place. However, no formation of quinoid structures was observed. Degradation of phenylcoumaran units was evident, α- Ether cleavage in phenylcoumarans could possibly lead to formation of stilbenes and stilbene derived chromophores. 相似文献
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乙型脑炎病毒SA14-14-2株NS3基因的克隆及原核表达 总被引:1,自引:1,他引:0
目的克隆并表达乙型脑炎病毒SA14-14-2株NS3编码区的基因片段,为重组蛋白进一步的功能研究奠定基础。方法提取乙脑病毒SA14-14-2株总RNA,用RT-PCR法扩增NS3-1、NS3-2基因片段,克隆入原核表达载体pET15bTAT中,构建重组原核表达质粒,转化大肠杆菌Rosetta2,IPTG诱导表达。表达产物经Ni2+亲和层析柱纯化后,进行Western blot鉴定。结果重组原核表达质粒pET15bTAT-NS3-1和pET15bTAT-NS3-2经酶切证明构建正确。表达的重组蛋白相对分子质量约为27000和20000,主要以包涵体的形式表达。重组蛋白纯化后纯度可达80%以上,并可被小鼠抗乙型脑炎病毒SA14-14-2株血清识别。结论已成功克隆了乙型脑炎病毒SA14-14-2株NS3-1和NS3-2基因,并在大肠杆菌Rosetta2中获得表达。 相似文献
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Reactive Oxygen Spiecies (ROS) such as superoxide anion radical (.O(2)(-)) act as signals for the activation of stress-response and defense pathways. However, excess ROS generated by perturbing .O(2)(-) homeostasis stimulated many environmental stress, including intense light, drought, temperature stress, herbicides, induce high radical toxicity. Consequently, quantitative analysis of .O(2)(-) is a subject of intense research, since most of ROS are derived from .O(2)(-). Iron meso-tetrakis(3-thienyl)porphyrin complexes were electropolymerized onto a Au wire electrode. The modified Au electrode were applied to .O(2)(-) sensor to detect catalytic oxidation current of .O(2)(-) which was generated as an intermediate during the oxidation of xanthine by catalystic XOD. It was revealed that the sensor was quantitative to measure .O(2)(-). The modified Au electrode were applied to measure oxidation current of .O(2)(-) in mung beans under environmental stress condition. Plants were grown in atmosphere, 25 degrees C and in black darkness. The other plants were exposed to oxygen excess. The oxidation current of .O(2)(-) were increased plants were grown by high-oxygen environment compared to plants were grown at atmosphere. This experiment was indicated that environmental stress such as hyperoxia induced excess .O(2)(-) and Au wire sensor using iron porphyrin complexes is capable of .O(2)(-) detection in plants under environmental stresses. 相似文献
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为探究农业生物质燃烧性能,以油泥与3种秸秆(玉米秸秆、豆秆、麦秆)为试验原料进行等温燃烧试验,对混合成型燃料的燃烧特性进行了研究,并对反应动力学进行分析。结果表明,随着温度的升高3种混合成型燃料的燃烧最大峰值提前,燃尽时间明显缩短,最大失重速率增加,但燃烧失重率最后基本保持一致。3种混合成型燃料在750~950℃温度下等温燃烧过程的反应级数分别为1.2~1.4、0.9~1.1和1.0~1.2,活化能分别为55~57、50~53和49~55 kJ/mol,指前因子分别为57~113、35~74和76~103 s-1。3种混合成型燃料的燃烧过程遵循燃烧动力学基本方程的规律,并可用一级反应来描述,秸秆种类对混合成型燃料燃烧性能影响不显著。 相似文献