胰岛素活性结构在水合离子液体中的稳定性

离子液体以其独特的、可修饰的分子结构以及优良的物理化学性质被应用于蛋白质的稳定性研究。采用分子动力学模拟方法及微量热法,研究热敏性蛋白药物胰岛素在不同水质量分数下水合离子液体中活性结构的稳定性,并深入分析离子液体与胰岛素之间的相互作用及水分子与蛋白质稳定性之间的关系。研究结果表明,当水质量分数低于25.00%时,胰岛蛋白的热变性温度能保持在68℃以上。且通过模拟分析得出,含水量25.00%的水合离子液体体系中,大量阴、阳离子在胰岛蛋白表面聚集,并通过较强的静电相互作用吸附在其表面,从而对蛋白质的活性结构展现出良好的稳定效果。结合宏观实验研究及微观动力学计算阐释了不同水含量的离子液体稳定蛋白质的作用机理,并为离子液体对蛋白质的稳定作用研究提供了一种新的分析方法。     

胰岛素活性结构在水合离子液体中的稳定性

离子液体以其独特的、可修饰的分子结构以及优良的物理化学性质被应用于蛋白质的稳定性研究。采用分子动力学模拟方法及微量热法,研究热敏性蛋白药物胰岛素在不同水质量分数下水合离子液体中活性结构的稳定性,并深入分析离子液体与胰岛素之间的相互作用及水分子与蛋白质稳定性之间的关系。研究结果表明,当水质量分数低于25.00%时,胰岛蛋白的热变性温度能保持在68℃以上。且通过模拟分析得出,含水量25.00%的水合离子液体体系中,大量阴、阳离子在胰岛蛋白表面聚集,并通过较强的静电相互作用吸附在其表面,从而对蛋白质的活性结构展现出良好的稳定效果。结合宏观实验研究及微观动力学计算阐释了不同水含量的离子液体稳定蛋白质的作用机理,并为离子液体对蛋白质的稳定作用研究提供了一种新的分析方法。     

热敏性物料干燥实验研究

根据聚碳酸酯产品的热敏性要求,对干燥工艺进行了分析研究,设计流化床干燥系统。实际应用表明,流化床系统具有产品质量符合要求、干燥效果好、操作使用方便等优点。     

离子液体中胰岛素结构稳定性的分子动力学模拟

离子液体作为一种新型绿色溶剂,由于其独特的物理化学性质,被广泛应用于蛋白质的稳定性研究。选用热敏性蛋白药物胰岛素作为研究对象,采用分子动力学模拟方法,从分子层面上研究不同种类的离子液体对胰岛素结构的稳定效果。结果表明,与纯水体系相比,在常温下离子液体能够有效地稳定胰岛素的分子结构,且体系中阴离子的氢键碱性越弱,阳离子的烷基链越短,对胰岛素分子结构的稳定作用越强。并深入分析不同烷基链长度的二氰胺类离子液体与胰岛素之间的相互作用,发现相较于长烷基链离子液体,短烷基链离子液体与胰岛素之间的相互作用更强,揭示了后者能更好地维持和稳定胰岛蛋白的分子结构。     

微波-对流干燥技术在聚丙烯酰胺生产中的应用

采用微波－对流干燥技术对高含水、粘度较大、过热表面易结壳的热敏性物料进行烘干试验,取得了较好的效果,解决了干燥领域的一大难题,并给出了烘干曲线及微波－对流干燥原理图,可供设计参考。     

离子液体中胰岛素结构稳定性的分子动力学模拟

离子液体作为一种新型绿色溶剂,由于其独特的物理化学性质,被广泛应用于蛋白质的稳定性研究。选用热敏性蛋白药物胰岛素作为研究对象,采用分子动力学模拟方法,从分子层面上研究不同种类的离子液体对胰岛素结构的稳定效果。结果表明,与纯水体系相比,在常温下离子液体能够有效地稳定胰岛素的分子结构,且体系中阴离子的氢键碱性越弱,阳离子的烷基链越短,对胰岛素分子结构的稳定作用越强。并深入分析不同烷基链长度的二氰胺类离子液体与胰岛素之间的相互作用,发现相较于长烷基链离子液体,短烷基链离子液体与胰岛素之间的相互作用更强,揭示了后者能更好地维持和稳定胰岛蛋白的分子结构。     

微波—对流干燥技术在聚丙烯酰胺生产中的应用

采用微波－对流干燥技术对高含水、粘度较大、过热表面易结壳的热敏性物料进行烘干试验,取得了较好的效果,解决了干燥领域的一大难题,并给出了烘干曲线及微波－对流干燥原理图,可供设计参考。     

真空混合烘干技术在塑料加工行业中的应用

利用真空干燥原理,以双螺杆挤出机产生的废热为热源,采用单螺旋混合干燥机在真空状态下混合烘干物料.实践表明,该真空混合烘干技术节能效果明显,可满足物料的干燥技术要求,尤其适用于热敏性塑料的干燥.     

XLGJ—A型旋转列管干燥机干燥湿法活性碳酸钙应用成功

唐山化工机械有限公司工程技术人员 ,对旋转列管干燥机在轻质碳酸钙的生产应用中不断创新、改进的基础上 ,研制开发了湿法活性碳酸钙专用XLGJ -A型旋转列管干燥机 ,已投入运转 ,获得成功。单台能力达到 10 0 0 0t/a。每吨活性碳酸钙蒸汽消耗约 0 .8～ 1.0t左右。　　湿法活性碳酸钙 ,因其粒子表面包覆有表面活化剂 ,属于热敏性物料 ,其干燥温度受一定限制 ,干燥温度高低又与表面活性剂种类和配方有关 ,同时由于湿法活性钙是在碳化浆液状态下对碳酸钙的原始结晶颗粒进行包覆活性化 ,干燥过程的粉体分散性能好 ,粒径细而均匀 ,其流变性极强…     

热敏性物料干燥系统的优化设计

针对产品要求最终湿含量非常低的热敏性物料的干燥,提出了一种分段多室卧式流化床干燥系统。建立了流化床干燥系统数学模型,以总的经济指标为目标函数,对该系统进行优化。并用此方法对３０００ｔ／ａＰＴＳＣ的干燥进行了优化设计。     

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。