非离子态氨对转“全鱼”生长激素基因鲤鱼的急性毒性和慢性毒性

在自然水体和人工水体中氨氮对鱼类是有毒的.利用静水更新式生物测试研究了非离子态氨对转基因鲤鱼和对照鱼的96h急性毒性实验和21d慢性毒性实验.通过96h非离子态氨急性毒性实验发现,转基因鲤鱼的非离子态氨氮24,48,72和96h半数致死浓度(LC50)(2.64,2.44,2.28和2.16mg/L)分别比对照鲤鱼相应的24,48,72和96h半数致死浓度(LC50)(2.70,2.64,2.52和2.33mg/L)略低,没有显著性差异;但在不同非离子态氨氮(3.86,3.29和2.09mg/L)胁迫下

Determination of Gallic Acid Content in Extract of Canarium album (Lour.) Raeusch Fruit and Its Radical Scavenging Activity

采用高效液相色谱法测定橄榄果实甲醇提取物中没食子酸的含量,并用二苯基苦基苯肼自由基(dPPH.)法研究了橄榄果实提取物的自由基清除能力。没食子酸质量浓度在8.4--42 Mg/l范围内,没食子酸峰面积与其进样量呈良好的线性关系(r=0.999 3),没食子酸平均质量分数4.03%,相对标准偏差(rSd)(n=6)1.77%,平均回收率98.75%,rSd(n=6)1.21%。该方法简单灵敏,准确可靠,重复性好。橄榄果实甲醇提取物具有较高的自由基清除能力,dPPH.的半数抑制浓度(IC50)为40.14 Mg/l。The content of gallic acid in extract of white canarytree(Canarium album(Lour.)Raeusch) fruit was determined by HPLC.The radical scavenging activity of extract was determined by 1,1-diphenyl-2-picrylhydrazyl(DPPH) assay.The linearity of gallic acid content was over the range of 8.4-42 mg/L with good linear correlation(R=0.999 3).The mean value of gallic acid content was 4.03 %,with relative standard deviation(RSD)(n=6)1.77 %.The average recovery was 98.75 % with RSD(n=6)1.21 %.The determination method is simple,sensitive,accurate,reliable and with good reproducibility.C.album fruit extract showed a very good DPPH radical scavenging activity(IC50) 40.14 mg/L.国家自然科学基金资助项目(30671646);教育部新世纪优秀人才支持计划项目(NCET-07-0725

Preparation and Antioxidant Activity of Cyanidin from Condensed Tannins Extracted from Calyx of Bruguiera gymnorrhiza

利用MALDI-TOF MS分析了红树植物木榄花萼缩合单宁的结构单元组成类型、平均聚合度和平均分子质量。并以木榄花萼缩合单宁为原料,通过HCl-正丁醇法酸解反应制备了花青定粗产品,同时测定了花青定粗产品对二苯基苦基苯肼自由基(DPPH.)的清除能力及铁离子还原/抗氧化能力(FRAP)。结果表明:木榄花萼缩合单宁结构单元组成类型主要为儿茶素或表儿茶素,平均聚合度为7.5,平均分子质量为2081.60u;花青定粗产品具有较强的清除自由基能力,DPPH.半数抑制浓度(IC50)为43.889mg/L,并具有较高的FRAP((7.718±0.109)mmol/g)。Type of structural units,degree of polymerization and mean molecular weight of condensed tannins extracted from calyx of large red mangrove (Bruguiera gymnorrhiza) were characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Crude cyanidin products were prepared from condensed tannins of B. gymnorrhiza by means of butanol/HCl reaction. In addition,the free radical-scavenging activity and antioxidant ability of crude cyanidin products were determined by using 1,1-diphenyl-2-picrylhydrazyl radical (DPPH·) and ferric reducing/antioxidant power (FRAP) model systems respectively. The results showed that catechin/epicatechin were the structural units occurring in condensed tannins of B. gymnorrhiza. Average degree of polymerization was 7.5,and mean molecular mass was 2 081.60 u. Crude cyanidin products showed a very good DPPH radical scavenging activity (IC50 of 43.889 mg/L) and ferric reducing/antioxidant ability ((7.718± 0.109)mmol/g).国家自然科学基金(30671646);; 教育部新世纪优秀人才支持计划(NCET-07-0725

Vietnam’s Claims to Insular Features and Maritime Space in the South China Sea and the Bases of Its Claims

张明亮,博士,暨南大学国际关系学院东南亚研究所副教授。电子邮箱:[email protected]。［文摘］越南在南(中国)海(以下简称“南海冶)的主权与权利要求包括两个类别:对南海岛礁的主权要求和对部分南海海域权利与管辖权的要求。越南政府于1979年和1982年发布两份白皮书,1988年4月又发布一份文件,这三份文件中的主要观点都被延续下来,成为越南对部分南海岛礁的主权要求的依据;越南提出权利要求的南海海域包括两类:一类是“黄沙群岛和长沙群岛冶周边的海域,另一类是越南依据本土陆地划定的领海基线所推算出的专属经济区和大陆架,从而对部分南海海域提出了权利要求。本文阐释了越南对南海岛礁与海域的权利要求及其依据。［Abstract］Vietnam’s claims to sovereignty and rights over the South China Sea (SCS) fall into two categories:claims to sovereignty over SCS insular features,and claims to rights and jurisdiction over SCS maritime space.The Vietnamese government issued two white papers in 1979 and 1982 respectively,and one document in April 1988.The main ideas of these three documents have been maintained to become the basis for Vietnam’s claims to sovereignty over some insular features in the SCS.The SCS maritime space which Vietnam claims includes two types:first,maritime space around the so-called“Hoang Sa and Truong Sa Islands;”second,exclusive economic zones and continental shelves calculated according to the territorial sea baseline drawn based on its mainland,which generate claims to part of the SCS maritime space.This article attempts to outline Vietnam’s claims to SCS insular features and maritime space as well as the bases of its claims.本文系国家社科基金重大项目《南海地区国家核心利益的维护策略研究》(项目编号:10zd&013)阶段性成果

Study on Structure of Tannin in Prunus salicina Lindl.Fruits and Its Antioxidant Activity

对李子果肉的总酚含量与可溶性缩合单宁含量进行了测定,并利用基质辅助激光解吸附离子化飞行时间质谱(MALDI-TOF MS)联合核磁共振(NMR)技术详细研究了李子果肉单宁的类型、聚合度及平均分子质量。同时用二苯基苦基肼自由基(DPPH·)法研究了李子果肉单宁的抗氧化活性。结果表明:李子果肉中总酚质量分数为8.29%±1.30%,可溶性缩合单宁质量分数为1.43%±0.93%;构成该单宁的黄烷-3-醇结构单元主要是表儿茶酚,在化学结构上属于原花青定类型,且大部分聚合物的结构单元之间存在A型和B型2种连接方式,平均聚合度为5.3,平均分子质量为1583.7u;李子果肉单宁具有较高的自由基清除能力,其半数有效浓度(EC)为57.98mg/L。Contents of total phenolics and extractable condensed tannins in Prunus salicina Lindl.fruits were determined.Type of condensed tannins,degree of polymerization and distribution of polymer were characterized by matrix-assisted laser desorption-ionization time-of-flight mass spectrometry(MALDI-TOF MS) and nuclear magnetic resonance(NMR) spectroscopy.The effects of tannins from P.salicina fruits on scavenging free radicals were determined by using 1,1-diphenyl-2-picryhydrazyl(DPPH·) free radical test.The results were showed as follows: total phenolics and extractable condensed tannins were 8.29 %±1.30 % and 1.43 %±0.93 %,respectively;Epicatechin was the basic units occurring in condensed tannins,A-type and B-type lin-kages were most common among the structural units of polymers.The average degree of polymerization was 5.3,and mean molecular weight was 1 583.7 u.EC50 value was 57.98 mg/L by DPPH· scavenging test.国家自然科学基金(40376026,30671646);; 教育部新世纪优秀人才支持计划(NCET-07-0725

Study on antioxidant activity of polyphenols from Canarium album fruits

开发利用天然抗氧化剂是当前食品科技发展的趋势,橄榄果实中富含各种多酚类物质,是理想的天然抗氧化剂。本文对橄榄中的多酚含量进行了测定,用二苯基苦基苯肼自由基(DPPH.)和铁离子还原/抗氧化能力测定(FRAP)法,研究了橄榄多酚提取物的自由基清除能力及抗氧化活性。结果表明:橄榄中多酚含量高达572.30±39.71mg/g干重;橄榄多酚提取物具有较高的自由基清除能力(IC50为40.14μg/mL)及较强的抗氧化能力(4.271mmol/LAAE/g)。Exploitalion and applieation natural is trend for development food technology,there are abundant of polyphenols which are the perfect natural antioxidant.Polyphenols content of Canarium album(Lour) Rauesch fruits were determined.In addition,the effects of polyphenols from C.album fruits on free radical-scavenging and antioxidant activity were determined by using 1,1-diphenyl-2-picryhydrazyl(DPPH·) radical scavenging activity and ferric reducing/antioxidant power(FRAP) model systems.The results showed as follows:polyphenols content were 572.30 ± 39.71mg/g DW;polyphenols extracted from C.album fruits showed a very good DPPH· radical scavenging activity(IC_ 50 of 40.14μg/mL) and ferric reducing/antioxidant power(4.271mmol/L AAE/g).The DPPH· radical scavenging activities were well proved with the ferric reducing/antioxidant capacity of the studied polyphenols.国家自然科学基金资助项目(40376026,30671646

A Convenient Method for Condon Adjustment by Using High-fidelity DNA Polymerase Amplification Property

在基因工程研究中,经常要涉及到对目的基因读码框进行调整的研究。本文报道了利用高保真DNA聚合酶扩增DNA后产生平末端的特性,及限制性内切酶对一重组的原核表达载体pET28a-HA进行读码框调整的研究,测序结果显示读码框按照预期设计正确调整,表明高保真DNA聚合酶可以用于DNA 3'凹陷端的补平,在DNA 3'凹陷端平滑化时多了一个有效的选择。The reading frame adjustment of target genes was often occurred in the study of gene engineering.The results of pET28-HA gene reading frame exactly adjustment showed high-fidelity DNA polymerase can be used generate blunt end from a DNA 5'-protruding end.The convenient method can be selected in the blunt of DNA 5'-protruding end

Study on the characteristics of Syzygium cumini L. pigment

以海南蒲桃成熟果实为原料提取天然色素,并对其理化性质进行了分析研究。同时比较了D-072、D-401、D-301-G、D-101、D-110、DF01六种树脂对该色素的静态吸附情况及不同极性解吸剂对吸附色素的树脂洗脱的效果,从中选择吸附和解吸附效果最好的树脂以及适合的解吸剂。研究表明:该色素在酸性条件下对热、金属离子和常用食品添加剂均具有较好的稳定性,对光稳定性稍差;D-072大孔吸附树脂对海南蒲桃色素吸附效果最好,色素吸附率达90.7%;解吸剂用含0.2%三氟乙酸的50%酸化乙醇,色素可被充分洗脱下来。此研究结果为以海南蒲桃成熟果实为原料来生产食用色素提供了理论依据。The stability of pigment which was extracted from the fruit of Syzygium cumini was studied. In addition, absorbing and separating Syzygium cumini pingment with macroreticular resin was also studied. Static absorption capacity of six resins(D-072, D-401, D-301-G, D-101, D-110, DF01) for the pigment was compared. From these resins, the one with the best absorpting and desorpting effect was elected. The results showed that this kind of pigment has a better stability toward heat, metal ion and common food additives under acidic condition, and it is more tolerable of heat than light. The adsorption ability of D-072 resin was the best and the adsorptive rate of pigment reached 90.7%. When 50% ethanol contained 0.2% TFA was used as desorptive solvent, the pigment could be sufficiently desorpted and the effect of desorption would be better. It has a great prospect in the exploration and application in food industry to produce the food pigment from the fruit of Syzygium cumini.国家自然科学基金项目(30671646

中国古代东沙群岛命名的考释

中国闽粤沿海渔民在长期的生产实践中最早发现了东沙群岛,并给予命名。在中国古代,尤其是清代,诸多的历史图籍较为详细地描绘和记述了东沙群岛的构成、地理方位和特征。考释东沙群岛之命名,在地名学和维护领土主权等方面的意义都是十分重大的。教育部人文社会科学青年基金项目“晚清时期中国南海疆域研究”阶段性研究成果(07JC770010