纳米氧化锌的生物法合成及固定脂肪酶的研究

采用植物乳杆菌合成了纳米氧化锌粒子并成功用于脂肪酶的固定化。将筛选得到的高耐硫酸锌的植物乳杆菌株LP4用于纳米氧化锌的合成,采用扫描电镜、透射电镜和X射线衍射等一系列分析测试手段对得到的产物进行了表征。结果显示合成的材料为直径9~35 nm球形颗粒,在359 nm处有最大吸收峰,晶体呈六方体纤锌矿结构,X射线衍射峰与标准纳米氧化锌对比结果一致,这些结果表明植物乳杆菌株LP4成功合成了纳米氧化锌。然后将合成得到的纳米氧化锌粒子用于固定假丝酵母（Candida sp.）脂肪酶,与普通氧化锌以及传统法合成的纳米氧化锌粒子相比,生物法合成的纳米氧化锌固定效果最好,固定化酶的酶活收率分别比普通氧化锌和传统纳米氧化锌提高114.2%和20.5%。论文还对该生物纳米固定化酶的pH和热稳定性以及重复使用性能进行了测定,结果表明酶固定化后稳定性明显提高,而且具有较好的重复使用性能。     

合成不同粒径大小的金纳米粒子的分析研究

金属纳米粒子中金纳米粒子作为其中最重要的一员,由于其具有独特的催化性能、光学性能、导电性能,使其在生物传感~([1])、催化、药物载体、基因芯片~([2])等众多领域有着广泛的应用。纳米金在各个应用中控制其特定形貌、尺寸大小、空间结构具有十分重要的意义,但又面临一定的合成挑战。本文针对合成不同粒径的纳米金采用了不同的合成方法,成功地合成出不同粒径大小的纳米金。     

磁-金纳米粒子的制备及其生物医学应用进展

综述了近年来磁-金纳米粒子的合成及其在生物医学成像诊断和生物医学治疗上的最新应用研究进展。从磁性纳米粒子的制备方法、磁-金纳米粒子的合成方法、磁-金纳米粒子作为成像造影剂用于生物医学多模态成像及“无背景”成像、磁-金纳米粒子作为诊疗一体化探针用于医学诊疗一体化几个方面进行了概述,并对磁-金纳米粒子未来的发展及应用前景进行了展望。     

β——环糊精包裹的金纳米粒子的制备和表征

用β-环糊精作还原剂还原氯金酸合成了金纳米粒子;同时,β-环糊精作为金纳米粒子的保护剂,防止生成的金纳米粒子的聚集。UV数据表明,溶液内含有金纳米粒子。TEM实验表明,β-环糊精还原氯金酸能生成β-环糊精包裹的球形金纳米粒子。     

N-(4-氨基丁基)-N-(乙基异鲁米诺)/血红素/金纳米三功能化氧化石墨烯材料的合成及性质研究

基于发光试剂N-(4-氨基丁基)-N-(乙基异鲁米诺)(ABEI),发光试剂催化剂氯化血红素(hemin)、金纳米粒子(Au NPs)和氧化石墨烯(GO)之间的非化学键作用合成了一种三功能化氧化石墨烯发光功能化复合材料。采用化学发光试剂ABEI作为还原剂,还原氯金酸在石墨烯表面合成了金纳米粒子,ABEI和hemin催化剂通过非化学键作用积聚在石墨烯表面。三功能化的石墨烯复合材料不仅具有良好的化学发光性能、良好的溶解性和水溶液的稳定性,而且为金纳米粒子为生物大分子提供了结合位点。     

前沿科研成果融入物理化学实验教学——金-聚丙烯酸铵双面神纳米粒子的合成

设计了一个还原法制备金溶胶,并进一步合成具有双面神结构的金-聚丙烯酸铵纳米粒子的本科生化学实验。首先,采用溶胶法合成金纳米粒子,然后,聚丙烯酸通过异向生长与金纳米粒子形成具有双面神结构的纳米粒子。本实验可以锻炼学生制备纳米材料的能力,熟悉金纳米粒子的制备方法及其纳米尺度的特殊性质,并掌握仪器设备的使用,认识纳米尺度可操控材料的结构,得到金-聚丙烯酸铵双面神纳米粒子,使学生进一步了解科学前沿,提升科学素养。     

DNA修饰纳米金溶胶的稳定性

纳米金在分子生物学、生物传感器等领域具有广阔的应用前景.针对纳米金在电解质溶液中易形成不可逆聚集的问题,通过紫外光谱、TEM、Zeta电位测试等表征,研究了DNA分子修饰对纳米金溶胶稳定性的影响.结果表明,所制备的纳米金粒子的初始Zeta电位与粒径有关,平均粒径为13 nm的金粒子对应-44.4 mV的电位;当加入钠离子缓冲液后,纳米金粒子迅速聚集沉积.紫外光谱的动力学特性曲线表明,经过与巯基相连的DNA修饰后,纳米金粒子能够在钠离子缓冲液中稳定存在.     

金纳米材料的合成方法进展

本文综述了金纳米材料的合成方法,主要对一维金纳米粒子中的金纳米线和零维金纳米粒子中的金纳米星的合成方法进行了简单介绍,并指出了其优点与不足。最后对未来金纳米材料的应用前景进行了展望。     

金纳米粒子的合成和应用

金纳米粒子以它独特的光学、电学和催化性质以及在纳米级电子线路中的应用潜力,受到人们越来越多的关注.主要介绍了金纳米粒子的合成方法(模板法、湿化学法、电化学法、扫描探针微影术、光化学还原法和声化学合成法等)、成长机理和应用,展望了金纳米材料未来的研究方向和发展趋势.     

亲和素引发金纳米粒子聚集的影响因素研究

首次以亲和素作为凝聚剂与金纳米粒子(表面未经修饰)作用,通过中和金纳米粒子表面负电使粒子间斥力减弱、距离减小而聚集。通过探讨亲和素浓度和体积、缓冲溶液浓度以及金纳米粒子尺寸等因素对金纳米粒子聚集程度的影响发现,当与金纳米粒子溶液反应的亲和素体积≤5μL时,PBS缓冲溶液中的离子对金纳米粒子影响可忽略;当与金纳米粒子溶液反应的亲和素的浓度介于50~100μg/mL时,金纳米粒子呈现最大程度的聚集;相比于较小尺寸的金纳米粒子,大尺寸的金纳米粒子更易聚集;3种尺寸的金纳米粒子的聚集程度都随亲和素浓度变化而改变。本实验将为以金纳米粒子聚集为基础的生物检测研究以及金纳米粒子自组装方面的深入研究提供可靠的文献资料。     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料，介绍了2005—2006年国外塑料工业的发展情况。提供了世界塑料产量、消费量及全球各类树脂生产量以及各国塑料制品的进出口情况。作为对比，介绍了中国塑料的生产情况。按通用热塑性树脂（聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂）、工程塑料（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序，对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况.按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯·硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、不饱和聚酯树脂、环氧树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍.