一种席夫碱铋配合物的合成及其与牛血清白蛋白的相互作用

在非水体系中,以邻香草醛缩甘氨酸席夫碱与8-羟基喹啉、无水氯化铋合成一种三元配合物,通过元素分析、热分析、光谱分析等表征手段,确定其化学组成为[Bi(C_(10)H_(10_NO_4)(C_9H_6NO)_2]。席夫碱以酚羟基中的氧和C=N双键中的氮与铋(Ⅲ)成键,8-羟基喹啉以氧、氮与铋(Ⅲ)双齿配位,形成五元螯环。采用荧光法研究配合物与牛血清白蛋白(BSA)在不同温度下的相互作用,可知发生静态荧光猝灭,配合物与BSA以摩尔比1∶1结合形成复合物,结合常数为6.21×10~4L/mol,ΔH和ΔS均大于0,说明结合力主要为疏水作用;同步荧光扫描发现色氨酸残基的发射波长红移,表明复合物的形成导致BSA的构象发生了变化。     

香草醛与牛血清蛋白的相互作用研究

运用紫外-可见吸收光谱(UV-Vis)和傅立叶红外光谱(FT-IR)研究了生理pH条件下香草醛与牛血清白蛋白(Bovine serum albumin,简称BSA)的相互作用以及Cr3+对香草醛与BSA的相互作用的影响,并求出了香草醛与BSA结合的结合常数,研究了Cr3+对香草醛与BSA的结合常数的影响,探讨了香草醛对BSA的二级结构的影响。     

溴酚蓝增敏邻二氮菲法测定自来水中的微量铁

在HAc-NaAc缓冲溶液(pH值为6.0)条件下,溴酚蓝对Fe2+与邻二氮菲的显色反应具有增敏作用,形成的络合物在三氯甲烷中的最大吸收波长为604am,表观摩尔吸收系数为ε604=1.64×104L·(mol·cm)-1,灵敏度提高了49%.Fe2+浓度在0～2.0mg·L-1范围内符合比尔定律,检出限为0.015 ...     

锌(Ⅱ) - 2,2''-联吡啶络合吸附波法测定血清白蛋白

在pH值6.3的HAc-NaAc介质中,血清白蛋白使锌(Ⅱ) - 2,2′-联吡啶络合物在-1.20 V(vs.SCE)处的络合吸附波还原峰电流降低,峰电流降低值与加入的牛血清白蛋白(BSA)或人血清白蛋白(HSA)的浓度在一定范围内呈线性关系.BSA和HSA的线性范围分别为0.5～40.0 mg·L-1、0.5～50.0 mg·L-1,检出限均为0.2 mg·L-1.应用该法测定了人血清样品中总蛋白含量,结果令人满意.     

用TBF测定人血清白蛋白的分光光度法

用分光光度法研究了四溴萤光黄二钠盐 (TBF)与人血清白蛋白 (HAS)在吐温 -60存在时的结合反应 ;在最佳反应条件下 ,以试剂空白为参比 ,TBF -HAS复合物的最大吸收波长在 5 45nm ,HSA的浓度在 0 .5～ 4.0mg/L范围内符合比耳定律 ,表观摩尔吸光系数ε=6.0 5× 1 0 6 L·moL- 1·cm- 1,Sandell灵敏度S =0 .0 1 1 2ug·cm- 2 。方法用于人血清中蛋白质总量的测定 ,与经典的考马斯亮蓝G— 2 5 0方法结果一致。     

微波消解—荧光光度法测定化学需氧量

探讨了一种微波消解制样、荧光光度法快速测定水样化学需氧量的新方法.确定最佳消解条件为:氢离子浓度1.0 mol·L-1、微波消解功率585 W、消解时间6 min,无需催化剂,当氯离子浓度小于800.0 mg·L-1时无需氯离子掩蔽剂.在激发波长为250 nm、发射波长为366 nm条件下用荧光光度法测定Ce(Ⅲ)的荧光强度.结果表明,荧光强度与COD值在0～200.0 mg·L-1范围内呈良好的线性关系,检测限为0.9 mg·L-1,回收率为94.4%～111.0%.     

光谱技术研究硫堇与牛血清白蛋白的结合反应

用荧光光谱、紫外可见吸收光谱和圆二色光谱技术研究了生理条件下硫堇(TH)与牛血清白蛋白(BSA)的结合反应.结果表明,硫堇借静电力与牛血清白蛋白发生相互作用并对牛血清白蛋白的荧光以静态方式猝灭,其结合常数为1.155×105L·mol-1、结合位点数为1.835、结合距离2.865 nm.同步荧光和圆二色技术证实TH对BSA的构像有影响.     

DBC-偶氮羧共振光散射法测定蛋白质

基于蛋白质对DBC-偶氮羧光散射增强的效应,拟定了一种测定蛋白质的新方法.在pH 4.1的Britton -Robinson(B-R)缓冲溶液中,蛋白质与DBC-偶氮羧结合,产生强烈的共振光散射.在362 nm处,共振光散射强度较大,且光散射强度与加入的蛋白质浓度在一定范围内呈线性关系,其中牛血清白蛋白(BSA)在0.05～7 mg·L-1、人血清白蛋白(HSA)在0.05～8 mg·L-1、溶菌酶(Lyso) 在0.05～7 mg·L-1.该法用于人血清总蛋白含量的测定,结果令人满意.     

加替沙星与亚甲基蓝的光度分析研究

研究了加替沙星与亚甲基蓝的显色反应,建立了测定加替沙星的单波长显色、退色可见分光光度法及双波长叠加可见分光光度法.在pH 2.5～6.5的酸性条件下,加替沙星(GATI)与亚甲基蓝(MTB)反应生成具有正吸收峰和负吸收峰的蓝色配合物,最大正吸收波长位于674 nm,最大负吸收波长位于646 nm,表观摩尔吸光系数(ε)分别为2.65×104L·mol-1·cm-1(正吸收)和1.36×104 L·mol-1·cm-1(负吸收),线性范围为0.2～17.0 mg/L(正吸收)和0.2～15.0 mg/L(负吸收),若采用双波长叠加测定,灵敏度将更高,加替沙星在一定浓度范围内遵从朗伯比尔定律.探讨了适宜的反应条件及主要分析化学性质.该法用于实际样品的测定,结果满意.     

雀儿舌头光谱性质及其与BSA相互作用的研究

通过荧光光谱法和紫外吸收光谱法研究了中药雀儿舌头(Leptopus Chinensis,LC)的光谱性质以及LC与牛血清白蛋白(BSA)之间的相互作用。研究了溶剂、提取时间、浓度、pH对雀儿舌头提取物荧光特性的影响。乙醇作为提取溶剂,提取时间设定为10 min,在中性条件下测定。在激发波长为280 nm和狭缝宽度为5 nm条件下,观察到BSA的荧光猝灭以及LC的荧光敏化。LC对BSA中酪氨酸和色氨酸残基的影响结果表明,LC与BSA中色氨酸残基之间发生了能量转移。     

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。