磁性淀粉微球固定化乙酰乳酸脱羧酶及应用

采用复合技术制备出粒径为 １００～３００ｎｍ的磁性淀粉复合微球。以此为载体采用溴化氰共价结合法、戌二醛交联法、物理吸附法固定化ａ一乙酰乳酸脱羧酶。以戌二醛交联法制备的磁性酶为最佳，其活力为１１３８．８Ｕ／ｇ微球，蛋白载量为８９．７ｍｇ／ｇ微球，比活为１２．６Ｕ／ｍｇ蛋白，活性回收率为５９．６％。并对其理化性质进行了研究：磁性酶最适温度３０℃，最适ｐＨ为５．０，热稳定性及酸碱稳定性均有所提高，磁性酶重复使用１０次，其相对活性仍保持在７７．２％。将磁性固定化ＡＬＤＣ用于啤酒发酵，磁性酶用量为 ８０Ｕ／Ｌ麦芽汁，主发酵温度为 １３℃，保持 １０ｄ，发酵后双乙酰含量降到 ０．１３×１０－６以下。     

磁性琼脂糖复合微球固定化纤维素酶的研究

以磁性琼脂糖复合微球为载体,采用物理吸附法,制备出磁性固定化纤维素酶。确定了固定化工艺条件：ｐＨ２－２,吸附时间８ ｈ,酶用量为１５０ ｍｇ／ｇ 微球,在最佳固定化条件下,磁性固定化酶的活力为１９１－７ Ｕ／ｇ 微球,蛋白载量为１００ ｍｇ／ｇ 微球,比活为１－９ Ｕ／ｍｇ 蛋白,活性回收率为７３－１ ％ 。并对磁性固定化酶的理化性质进行了研究：磁性固定化酶的最适温度（５５ ℃） 与天然酶相同,最适ｐＨ（５－０）较天然酶提高１－０ 个单位,磁性固定化酶Ｋｍ 值（４－１×１０ －３ｇ／Ｌ）较天然酶Ｋｍ值（７－８×１０－３ ｇ／Ｌ） 小,热稳定性较天然酶有所提高,磁性固定化酶重复使用１０ 次,其相对活性保持在６０ ％ 。     

一种磁性介孔硅纳米复合物的制备及其对顺铂前药的释放研究

文章通过在Fe_3O_4纳米粒外层包覆实心的nSiO_2后,再包裹一层mSiO_2,制备了一种MMSN,并将其负载顺铂前药Pt(Ⅳ),连结GnRH-a,成功制备了一种能靶向GnRH受体的磁性介孔硅纳米复合物,其对顺铂前药的负载量高,具有良好的超顺磁性以及磁靶向性能,并能够有效的实现药物释放。     

磁性导向柔红霉素白蛋白微球的研究

:采用乳化交联技术将磁性超微粒子及柔红霉素包埋于白蛋白内 ,化学交联固化后制得柔红霉素磁性白蛋白微球。该微球呈球形 ,平均粒径为 2 32 μm ,大小分布均匀 ,在 0 0 5T磁场中具强磁响应性 ,在水中分散性好。磁性微球载药量为 11 2 6 % (mg/mg) ,包封率为 75 0 % ;临界相对湿度CRH =81 6 %。含药微球在体外 12h释放完全 ,具一定的缓释作用。体内外磁定位实验表明 ,DNR磁性白蛋白微球制剂可浓集于靶区。稳定性考察表明所制微球稳定性良好。     

磁性壳聚糖微球固定化小牛白蛋白的研究

考察了磁性壳聚糖微球对磷酸氢二钠-柠檬酸缓冲溶液中小牛白蛋白的吸附性能,采用TEM(透射电镜)、XRD(X-射线粉末衍射)分析微球的形貌、组成,深入探讨了磁性壳聚糖微球用量对蛋白质脱除率的影响、吸附温度和蛋白质溶液离子强度对微球吸附性能的影响。实验结果表明,蛋白质脱除率随磁性壳聚糖微球用量增大而增大,最终趋于平稳;随着温度升高,微球吸附蛋白量先增加后减小;蛋白溶液离子强度增加,微球吸附蛋白量降低。     

磁性琼脂糖复合微球的制备和性质

采用乳化复合技术制备出粒径为２０～３００ｎｍ、分散系数为０．０９０～０．６０１、Ｆｅ３Ｏ４含量（ｗ）为７．５％～６１．３％的具有磁核的琼脂糖复合微球。该微球呈珠形,在４～９０℃的水介质中形成均匀稳定的分散液,在０．０５Ｗｂ／ｍ２的弱磁场中具强磁响应性。制备微球的最佳条件是：琼脂糖用量１２．５～８７．５ｍｇ／ｍｌ,氯化亚铁用量１５～１２０ｍｇ／ｍｌ,ｐＨ＞１０。     

γ-聚谷氨酸载药纳米微球的制备与研究

以γ-聚谷氨酸(γ-PGA)为材料,以顺铂(CDDP)作为装载药物,制备CDDP/PGA-PAE纳米微球。通过纳米粒度仪、红外光谱、可见光分光光度计对所制得的颗粒的粒径、粒度分布、Zeta电位、结构、包封率和载药量进行表征。以MTT实验进行体外初步药效学考察。结果显示,CDDP/PGA-PAE纳米微球制备成功,纳米微球的平均尺寸为148.4±4.7 nm, PDI=0.266±0.032。MTT实验结果显示,CDDP/PGA-PAE纳米微球浓度为100μg/mL时,人结肠癌LoVo细胞的存活率仅为33.80%±1.01%,说明CDDP/PGA-PAE纳米微球具有较高的CDDP利用率,为聚谷氨酸的应用提供了理论基础。     

微波辐射制备Fe3O4-聚苯乙烯复合磁性微球

采用微波辐射法制备了Fe3O4-聚苯乙烯复合磁性微球。通过Fe3O4磁流体的制备及改性,利用微波辐射使苯乙烯自聚反应能够在Fe3O4磁性颗粒表面顺利进行,最终得到复合磁性微球。实验考察了微波功率大小、聚合反应体系pH值、磁流体用量等反应条件的影响,通过红外谱图、热重谱图分析了产物的结构和热稳定性,利用沉降实验定性地表征了产物的磁响应性。结果表明：微波功率为130w时能迅速成功地制备出磁含量为24．47％的复合磁性微球。     

磁性壳聚糖微球的制备及其对2，4-二氯苯酚的吸附

采用反相悬浮聚合法合成了磁性壳聚糖微球,平均粒径不超过5μm。将其用于2,4-二氯苯酚的吸附研究。考察了吸附时间、吸附温度、DCP浓度以及磁性壳聚糖用量等因素对氯酚吸附的影响。结果表明,温度对吸附影响不大,最佳吸附时间为2h时,吸附剂磁性壳聚糖微球用量为1g。对DCP的吸附率在80％以上。在最佳条件下的吸附容量为1．70mg／g。     

Fe3O4／P（ST—AA）核—壳复合微球的制备和表征

本文以磁性氧化铁胶体粒子为种子，运用分散聚合法，制备出具有磁响应性Ｆｅ３Ｏ４／Ｐ（ＳＴ－ＡＡ）核－壳复合微球。考察了复合微球的形态及结构，测定了复合微球的粒径和磁响应性，研究了分散介质，引发剂，聚合单体和种子粒子等因素对复合微球形成的影响，适当调整有关反应条件，采用分散聚合法，可以使复合微球粒径达到２３．０μｍ，磁性氧化铁含量达到９．０ｍｇ／ｇ。     

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.     

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.     

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。