PiggyBac转座子介导的诱导细胞永生化转基因载体的构建及其整合效率的检测

【目的】构建在小鼠水平上实现多个目的基因的表达以及标记基因安全删除的转基因载体。【方法】以载体为模板,分别扩增SV40P neo、IRES、tk-PloyA,通过overlap PCR连接,并在两端添加方向相同的LoxP序列,构建转基因基本载体PB-NIT;然后通过overlap PCR扩增获得Tet-CMV-SV40 T-T2A-p 53-PolyA基因表达盒,将其插入PB-NIT中,构建载体PB-NIT-STP;最后将转录因子激活域 rtTA 通过同尾酶连接插入PB-NIT-STP,构建载体PB-rtTA-NIT-STP。【结果】经酶切和测序等鉴定,以上载体均正确;经转座活性鉴定,共转染转座子载体PB-rtTA-NIT-STP和转座酶载体比只转染转座子载体获得的阳性克隆数提高了20倍。【结论】得到了基于PiggyBac转座子的可用于正负向筛选和诱导目的基因表达的转基因载体。     

鲢鱼糜与淀粉复合系统的微波糊化特性

在2 450 MHz频率的微波处理条件下,为了考察添加鲢鱼糜对小麦粉面团糊化的影响,将小麦粉、鲢鱼糜、NaCl和去离子水按比例混合制成鲢鱼糜面团,面团中鲢鱼糜含量分别为0%,10%,20%和30%(w/w,质量百分比),对样品面团中淀粉的介电特性和糊化特性进行研究。结果表明,对于相同尺寸的面团样品,添加鲢鱼糜可改善面团样品在电磁场中的加热均匀性。随着温度的升高,面团的介电常数和介电损失率分别在20~23和9~12内波动并呈下降趋势,微波的穿透深度因淀粉的糊化略有上升。淀粉的糊化速率随温度的升高而下降。降低样品中淀粉的含量,会使面团糊化活化能由113.54 kJ/mol下降至59.96 kJ/mol。     

ZnCl2法制备的甘蔗渣活性炭对实验室有机废液的吸附特性

[目的]研究在不同条件下制得的海南甘蔗渣活性炭对有机实验室废水的处理能力。[方法]以ZnCl_2为活化剂,采用L16(43)正交试验法,研究以甘蔗渣为原材料制备活性炭的工艺,及其对实验室有机废液的吸附特性。[结果]影响活化效果的因素主次顺序为ZnCl_2溶液质量浓度、料液比、活化时间。在500℃时最佳活化的工艺条件为活化剂ZnCl_2溶液质量浓度180 g/L、料液比1.5、活化时间60 min,在该条件下制得的甘蔗渣活性炭对有机实验室废液的处理效果最好,活性炭粒径在100~120目为宜。[结论]该研究可为实验室有机废液处理提供科学依据。     

不同种类有机物对污染农田土壤重金属活性的影响

为了解施用不同种类有机物对污染农田土壤重金属行为的影响,布设了田间小区试验,观察研究施用6种不同类型有机物对土壤水溶性重金属和农作物对重金属吸收等的影响。试验设7个处理,分别为对照(不施有机肥)、施新鲜水稻秸秆、新鲜鸡粪、鸡粪堆肥、新鲜猪粪、猪粪堆肥和商品有机肥,动态检测土壤中水溶性重金属含量、田面水中重金属浓度及收获水稻籽粒中重金属含量的变化。结果表明,与不施有机物的对照处理比较,施用各类有机物在试验前期均可明显提高土壤中水溶性重金属和田面水中重金属的含量,总体上以施用新鲜猪粪的最高,其次为新鲜鸡粪,施用商品有机肥的最低。土壤中水溶性重金属含量随试验时间增长逐渐下降。施用各类有机物对水稻籽粒中重金属的积累影响不明显。土壤中水溶性重金属及田面水中重金属含量均与相应的水溶性碳(DOC)浓度呈显著相关性,表明因有机物施用增加土壤中DOC浓度可能是土壤中水溶性重金属含量增加的主要原因;而不同有机物对土壤重金属活性影响的差异可能与有机物本身的分解程度及可释放DOC大小有关。但施用有机物引起的农田土壤水溶性重金属含量的增加是暂时的,对水稻生长后期籽粒中重金属积累的影响不明显。     

Bromine Accumulation in Some Crops and Grasses as Determined by Neutron Activation Analysis

Till now information on bromine (Br) in the environment is still incomplete. The purposes of this research were the following: to study accumulation of Br in plants grown under different environmental conditions and to assess the factors controlling Br uptake by different plant species when the plants grow in soil uncontaminated with Br. For the determination of Br and other elements, neutron activation analysis was used. This method allows for determining a wide range of elements in various samples with high sensitivity and accuracy. Model tests and greenhouse experiments demonstrated different abilities of plants to uptake Br from various media and transfer it from roots to upper plant parts. It was shown that the main source of Br for a plant was soil. As a result of the plant growth concentration of Br in the rhizosphere soil decreased. The characteristics of soil have a pronounced effect on the Br uptake by plants.     

机械活化木薯淀粉的粉体综合特性研究

[目的]采用自制的高能效搅拌磨对木薯淀粉进行机械活化,研究机械活化对木薯淀粉粉体综合特性的影响。[方法]采用BT-1000粉体综合特性测试仪分析不同活化时间木薯淀粉的粉体综合特性。[结果]随着机械活化时间的增加,木薯淀粉的休止角、崩溃角、平板角均有所降低,差角和分散度增大,卡尔系数降低,孔隙度增大。[结论]经过机械活化后,木薯淀粉流动性、喷流性增强,压缩度降低,孔隙度提高。     

Biological Activities of Aqueous and Organic Extracts from Tropical Marine Sponges

We report on screening tests of 66 extracts obtained from 35 marine sponge species from the Caribbean Sea (Curaçao) and from eight species from the Great Barrier Reef (Lizard Island). Extracts were prepared in aqueous and organic solvents and were tested for hemolytic, hemagglutinating, antibacterial and anti-acetylcholinesterase (AChE) activities, as well as their ability to inhibit or activate cell protein phosphatase 1 (PP1). The most interesting activities were obtained from extracts of Ircinia felix, Pandaros acanthifolium, Topsentia ophiraphidites, Verongula rigida and Neofibularia nolitangere. Aqueous and organic extracts of I. felix and V. rigida showed strong antibacterial activity. Topsentia aqueous and some organic extracts were strongly hemolytic, as were all organic extracts from I. felix. The strongest hemolytic activity was observed in aqueous extracts from P. acanthifolium. Organic extracts of N. nolitangere and I. felix inhibited PP1. The aqueous extract from Myrmekioderma styx possessed the strongest hemagglutinating activity, whilst AChE inhibiting activity was found only in a few sponges and was generally weak, except in the methanolic extract of T. ophiraphidites.     

利用低温竹炭制备竹活性炭初步研究

选用低温竹炭为原料、氢氧化钾为活化剂,制备不同炭碱比和不同活化时间的竹活性炭。运用傅立叶红外光谱议(FTIR)、比表面积测定仪(BET)等仪器对竹活性炭表面官能团、比表面积和孔径结构及比电容进行了测试和分析。结果表明,炭碱比1:4、活化温度700℃、活化时间3h条件下制备的竹活性炭,比表面积为2897.7m2/g,总孔容为1.340cm3/g,平均孔径为2.59nm,亚甲基蓝吸附值为27.7ml/0.1g,碘吸附值为1920mg/g,作为超级电容器(EDLC)的电极,其比电容为114.4F/g。     

矿区重金属污染土壤中铅镉抗性细菌的筛选及其活化作用研究

从广西大新铅锌矿区重金属污染土壤中分离筛选出生长良好、产酸能力强的镉抗性菌株K1和铅抗性菌株K2,经革兰氏染色呈阴性,杆状菌体。菌株K1和K2的最适生长温度均为28℃,最适pH值为7和8。将菌株K1和K2分别接种到添加不溶性镉、铅的液体培养基（28℃培养48h）和含有固定态镉、铅的土壤（28℃培养5d）中,结果液体培养基中接菌处理比不接菌对照有效态镉、铅含量分别增加844．62％和370．48％,pH值分别降低2．95和2．07;土壤中接菌处理比不接菌对照有效态镉、铅含量分别增加42．42％、19。23％。说明两菌株具有较强的重金属镉、铅活化能力,可作为试验材料应用于抗性菌株强化植物富集重金属镉、铅研究中。