335弱碱性阴离子交换树脂对甘草酸的吸附过程

研究了335弱碱性阴离子交换树脂对甘草酸的吸附过程。拟合得到的吸附等温线方程为:c1/[q×(329-c1)]=0.035 8 1.872(c1/329),符合BET方程,计算得出335树脂的饱和吸附量是524.2 mg.g-1。通过吸附动力学曲线的研究,表明该树脂属于慢型吸附类型,得到树脂对甘草酸的吸附穿透曲线,穿透容量为42.00 mg.g-1,饱和容量近似为203.0 mg.g-1,交换柱的利用率小于0.206 9。用碱性洗脱液不易将树脂上吸附的甘草酸洗脱下来,利于甘草浸膏溶液中甘草酸和其它组分的分离。     

Design and characterization of a microfluidic packed bed system for protein breakthrough and dynamic binding capacity determination

A 1.5 μL ion exchange chromatography column to accommodate resins used for biopharmaceutical processing has been designed to produce breakthrough curves and to quantify dynamic and maximum protein binding capacities. Channels within a glass chip were fabricated using photolithography and isotropic etching. The design includes a 1 cm long microfluidic column in which compressible, polydispersed porous agarose beads (70 μm mean diameter) were packed using a keystone method where particles aggregate in a narrow channel. The depth of the column is such that two bead layers exist. The fabrication technique used forms Cartesian geometries as opposed to circular cross sections found in standard columns. The voidage was therefore higher than standard values when measured by 3D confocal microscopy. In conjunction with microscopic techniques, the column allows visualization of events within the bed such as adsorption profiles that would otherwise be difficult to observe. In this work, the binding of fluorescently labeled protein during isocratic loading was used to generate breakthrough from the microcolumn. Useful breakthrough curves were achieved using mobile phase velocities from 60 to 270 cm h^?1. Calculated dynamic binding capacities were compared well with previously published data on conventional scale columns. The microfluidic chromatography column described here thus allows study of process scale chromatography behavior at scales 20,000 times smaller than in current practice. The work described in this article is representative of the proof of principle of a potentially powerful tool for the generation of microfluidic process bed data for the biopharmaceutical industry. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009     

白纹伊蚊和埃及伊蚊对基孔肯雅病毒的易感性和传播性的研究

用４株基孔肯雅病毒经口感染白纹伊蚊和埃及伊蚊,进行了易感性和传播性的研究。结果表明,这两种蚊虫对基孔肯雅病毒易感。无论白纹伊蚊或埃及伊蚊,感染后第５－６天即可通过吸血将病毒传播给乳鼠,至第８－１３天,传播率可高达５５．５５％－１００％。感染蚊亦可经叮咬将病毒传播给小鸡。埃及伊蚊的易感性和传播率高于白纹伊蚊。实验还发现,不同来源毒株之间存在一定差异,如分离自云南白纹伊蚊的Ｍ８１株的感染率和传播率均高于其它毒株。这些结果表明,白纹伊蚊和埃及伊蚊在基孔肯雅病毒的保存和传播中起重要作用。     

登革热的传播模式、蚊媒及防控

在自然界存在两种登革热传播模式：人－伊蚊－人循环,蚊媒是埃及伊蚊与白纹伊蚊。猴－伊蚊－猴循环,蚊媒是白纹伊蚊与白雪伊蚊群。我国学者首先于1975年从无输入性病例的我国西南边疆山林地区的白纹伊蚊体内分离到登革热病毒4型,白纹伊蚊承担两种传播模式的中介。本研究介绍了埃及伊蚊与白纹伊蚊的生态习性与全球及在中国的分布。认为在我国厦门地区迄今为止还未曾发现过埃及伊蚊的存在,也简介了沃尔巴克体新技术防控蚊媒研究的进展。     

Anti-mosquito antibodies reduce the susceptibility of Aedes aegypti to arbovirus infection

Aedes aegypti (L.) mosquitoes showed a significant reduction in susceptibility to infection with Ross River virus and Murray Valley encephalitis virus when they were fed on a blood-virus mixture containing rabbit antibodies to mosquito midgut components. Presence of the antibodies did not demonstrably affect virus titres in infected mosquitoes, nor the transmission of virus from infected mosquitoes to vertebrates.     

Prospective field study of transovarial dengue‐virus transmission by two different forms of Aedes aegypti in an urban area of Bangkok,Thailand

A prospective field study was conducted to determine transovarial dengue‐virus transmission in two forms of Aedes aegypti mosquitoes in an urban district of Bangkok, Thailand. Immature Aedes mosquitoes were collected monthly for one year and reared continuously until adulthood in the laboratory. Mosquitoes assayed for dengue virus were processed in pools and their dengue virus infection status was determined by one‐step RT‐PCR and nested‐PCR methods. Of a total 15,457 newly emerged adult Ae. aegypti, 98.2% were dark and 1.8% of the pale form. The results showed that the minimum infection rate (MIR) by transovarial transmission (TOT) of dengue virus during the one‐year study ranged between 0 to 24.4/1,000 mosquitoes. Dengue virus TOT increased gradually during the hot summer months, reaching a peak in April‐June, while dengue cases peaked in September, a rainy month near the end of the rainy season. Therefore, mosquito infections due to TOT were prevalent four months before a high incidence of human infections. TOT dengue virus infections occurred in both forms of Ae. aegypti. All four dengue serotypes were detected, with DEN‐4 predominant, followed by DEN‐3, DEN‐1, and DEN‐2, respectively.     

登革热媒介昆虫抗药性的研究进展

近年来,登革热在全球的流行迅速增长,埃及伊蚊Aedes aegypti(L.)和白纹伊蚊Aedes albopictus(Skuse)是登革热传播的主要媒介。目前,化学防治仍然是防治蚊虫的主要手段,每年化学杀虫剂的大量使用直接或间接地导致其产生了抗药性。关于埃及伊蚊和白纹伊蚊的抗药性研究,主要集中于DDT、有机磷和拟除虫菊酯类杀虫剂导致的抗药性,并已深入到抗药性分子机理的研究。文章就埃及伊蚊和白纹伊蚊对杀虫剂诱导的抗药性现状及抗性机理的研究进展进行综述。