木犀草素-锌（Ⅱ）配合物的制备及清除自由基活性研究

为增强木犀草素的生物活性将其制成锌（Ⅱ）配合物,采用了紫外、红外、元素分析及核磁共振1H谱的方法对配合物进行了结构表征,并测定了该配合物的稳定常数。抗氧化性试验采用了DPPH·法和水杨酸法分别测定了木犀草素-锌（Ⅱ）配合物对（DPPH·）自由基和羟自由基（·OH）的清除作用。结果表明：木犀草素的5OH～4C=O和一个锌离子发生配位形成木犀草素-锌（Ⅱ）配合物;该配合物比较稳定,稳定常数为：βn=4.03×10^7;木犀草素锌（Ⅱ）配合物能有效清除DPPH·和·OH自由基,其清除能力均强于木犀草素,对DPPH·自由基的清除作用略高于Vc,对·OH自由基的清除作用与Vc相接近,最大清除率分别为89.37%和85.10%,说明木犀草素-锌（Ⅱ）配合物是一种较强的自由基清除剂。     

壳聚糖及其金属配合物体外抗自由基活性的研究

用分光光度法,分别对壳聚糖和壳聚糖与钙离子的配合物清除超氧阴离子自由基(O2-.)的效果进行了测定。结果显示,壳聚糖对O2-.的清除率可达73.1%,壳聚糖与钙离子的配合物对O2-.清除率可高达80.7%。实验结果表明,壳聚糖及其与钙离子的配合物具有较好的抗氧化作用。     

大黄素和维生素C清除自由基的协同作用研究

研究了大黄素、维生素C、大黄素和维生素C混合体系清除羟基自由基和超氧阴离子自由基的能力。结果表明,大黄素对·OH和O2-·清除率为30.8%和68.78%;维生素C对·OH和O2-·的清除率为57.36%和72.65%;大黄素与维生素C混合后有协同作用,对·OH和O2-·的清除率可达到99.40%和93.38%。     

紫甘薯花青素的功能特性研究

采用抗坏血酸和BHT作为对照,测定了紫甘薯花青素的还原能力、对食用油脂的抗氧化能力及对.OH自由基和O2-.自由基的清除能力。结果表明,当浓度大到0.5mg/mL时,其还原能力接近抗坏血酸;在豆油基质中紫甘薯花青素的抗氧化活性高于BHT;在试验质量浓度范围内,紫甘薯花青素对.OH自由基的清除率为81.2%,活性略低于抗坏血酸;对O2-.自由基的清除率可达91.3%,活性强于BHT。     

染料木黄酮钙配合物的合成、表征及清除自由基和抑菌活性

以染料木黄酮和氢氧化钙为原料合成了染料木黄酮钙配合物,并采用红外光谱、紫外光谱、热重分析及核磁共振等手段对其结构进行了表征。采用邻苯三酚自氧化法、Fenton反应-邻二氮菲光度法和DPPH自由基方法分别测定配体与配合物清除超氧自由基、羟基自由基和DPPH自由基的能力,并且考察了它们的抑菌性质,测定了其抑制大肠杆菌、绿脓杆菌、李斯特氏菌的能力。结果表明:染料木黄酮以分子中的4位羰基O和5位羟基O与Ca2+配位而形成分子式为[Ca(C15H9O5)2].2H2O的配合物。在相同浓度下,配合物清除超氧自由基和羟自由基的能力明显强于配体,而清除DPPH自由基的能力仅略有增强。配体及其配合物对大肠杆菌、李斯特氏菌、绿脓杆菌都有一定的抑菌效果,配合物的抑菌性仅略高于配体。     

黄山贡菊提取物对羟自由基清除作用

采用邻二氮菲—Fe(Ⅱ) /H2 O2 体系产生羟自由基(·OH) ,用分光光度法(波长5 36nm)研究了黄山贡菊提取物对·OH的抑制和清除作用。结果表明:黄山贡菊提取物对·OH具有显著的抑制和清除作用。     

罗汉果提取液对自由基的清除作用

以邻苯三酚自氧化产生超氧自由基(02-),Fenton反应产生羟自由基(.OH),用分光光度法测定罗汉果提取物对O2-和.OH的清除作用。结果表明,罗汉果提取物对O2-和.0H均有显著清除作用。     

D-氨基葡萄糖与硝酸铕、铽配合物的合成及光谱分析

用D-氨基葡萄糖盐酸盐分别与硝酸铕和硝酸铽反应,制备了氨基葡萄糖-铕、氨基葡萄糖-铽两种配合物,并研究了配合物的红外光谱、紫外光谱和X射线光电子能谱(XPS)。配合物紫外的λmax发生了明显紫移,在远IR区Glu-Eu配合物中出现的新的吸收峰206 cm-1和254 cm-1可分别归属于νEu-O和νEu-N,在Glu-Tb配合物中出现的新的吸收峰203 cm-1和252 cm-1可分别归属于νTb-O和νTb-N,XPS表明氨基葡萄糖-Ln中氨基葡萄糖的N和O原子上的电子云密度减少,孤对电子转移,稀土离子得到电子。     

梵净山野生藤茶中二氢杨梅素的提取及体外抗氧化研究

研究梵净山野生藤茶中二氢杨梅素的提取及体外抗氧化。采用超声波辅助法从梵净山野生藤茶中提取二氢杨梅素,以1,1-二苯基-2-苦基肼自由基(DPPH·)和羟自由基(·OH)二种不同自由基体系研究二氢杨梅素的活性清除能力。结果表明:在实验浓度范围内,二氢杨梅素清除DPPH·的能力高于芦丁,二氢杨梅素浓度达到50 mg/L时,其清除率大于Vc,达到72.58%,随着二氢杨梅素浓度的增加,其清除·OH的能力逐步提高,最高可达到55.05%。因此,梵净山野生藤茶中二氢杨梅素具有较强的抗氧化能力。     

呋喃甲醛缩D-氨基葡萄糖Schiff碱及Cu(Ⅱ)配合物的合成与表征

在冰盐浴条件下,用醋酸钠调节p H=6~7,以呋喃甲醛和D-氨基葡萄糖盐酸盐为原料(n1︰n2=1︰1),用乙醇与乙醚的混合溶液为溶剂,合成了呋喃甲醛缩D-氨基葡萄糖Schiff碱及其铜(Ⅱ)配合物。通过IR、UV-Vis、摩尔电导率测定、熔点测定、差热-热重分析等手段对配合物进行了表征,并推断了配合物结构。     

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。