孔雀石绿与蛋白质相互作用的电化学行为的研究

在pH 4.7的NaAc-HAc缓冲液中,孔雀石绿(MG)能与牛血清白蛋白相互作用形成复合物,使孔雀石绿在-0.72 V(vsSCE)处有一极谱还原峰峰电流下降,在最佳条件下,峰电流的下降值同牛血清白蛋白(BSA)的浓度在0.5～20 mg/L范围内呈线性关系,其线性回归方程为Δip(nA)=-4.78+41cBSA(mg/L),相关系数r=0.996(n=10),检出限为0.4 mg/L.可将该方法应用于血清样品的测定,结果满意.     

结晶紫与蛋白质相互作用的电化学行为的研究

结晶紫(CV)是一种三苯甲烷类染料,常用作生物染色剂和无机离子的显色剂,在pH4.5的NaAc-HAc缓冲液中结晶紫与蛋白质能够相互作用形成复合物,使结晶紫在-0.82 V(vsSCE)处的极谱还原峰峰电流下降,在最佳条件下,峰电流的下降值同牛血清白蛋白(BSA)的浓度在0.5~35mg/L范围内呈线性关系,其线性回归方程为Δip=38.7 728.84CBSA,相关系数r=0.998(n=10),检出限为0.2 mg/L。可将该方法应用于血清样品的测定,结果满意。     

环境中荷尔蒙类化合物2,4-二氯苯酚的紫外光谱法研究及应用

研究了环境中荷尔蒙类化合物2,4-二氯苯酚的紫外吸收光谱,最大吸收峰位于286nm,在该波长下,其吸光度与2,4-二氯苯酚的浓度在一定范围内符合朗伯比耳定律,据此建立了2,4-二氯苯酚的紫外光谱分析法。方法的线性范围5～50mg／L。线性方程为A=0．0125x 0．0158,相关系数r=0．9991,测定质量浓度为20mg／L的2．4-二氯苯酚(n=10)的相对标准偏差为2％,方法的检出限为0．48mg／L。用本方法测定上海市苏州河中的2,4-二氯苯酚含量。结果令人满意。回收率为92．0％～104．5％。     

用胭脂红酸极谱分析法测定人血清白蛋白的研究

在pH值为4.0的Britton-Robinson(B-R)缓冲溶液中,胭脂红酸在滴汞电极上-0.54V(vs.SCE)处有一个灵敏的极谱还原峰,加入人血清白蛋白(HSA)后,两者之间发生结合反应形成复合物,其还原峰电位不变,而还原峰电流明显下降。峰电流的降低与蛋白质浓度在一定范围内成正比,优化了结合反应条件和电化学测定条件,建立了测定血清白蛋白的电化学分析新方法,应用于人血清白蛋白的测定,线性范围为2.0～70.0mg·L-1。考察了共存物质的影响,并应用于人血清样品中蛋白质含量的测定,结果与传统的考马斯亮蓝G-250光度法一致。本方法简便、准确、灵敏,选择性和重复性好。     

罗丹明S光度法测定痕量二氧化氯

在pH为9．5的NH4Cl—NH3缓冲溶液中,罗丹明S在525nm处有一最大吸收峰。当加入二氧化氯后,其吸收峰降低,在525nm波长处的吸光度降低值与二氧化氯质量浓度在0．050—5．0mg／L范围呈良好线性关系,检出限(3倍标准偏差)为0．01mg／L ClO2。据此建立了一个灵敏、简便、快速、准确地测定水中痕量二氧化氯含量的方法．用于样品分析,结果令人满意。     

吡啰红B作为电化学探针线扫极谱法测定透明质酸

在pH 3.5的Britton-Robinson(B-R)缓冲溶液中,吡啰红B在-1.01 V(vs.SEE)处有一个灵敏的线性扫描二阶导数极谱还原峰,当加入一定量的透明质酸后,由于此条件下吡啰红B带正电荷,而透明质酸带负电荷,两者之间通过静电引力作用形成一种生物超分子复合物,导致溶液中吡啰哕红B的游离浓度降低,相应的还原峰电流降低而峰电位基本保持不变.优化了结合反应条件和电化学测定条件,考察了常见干扰物质对测定的影响.在最佳实验条件下,还原峰电流的降低值与透明质酸的浓度在30.0～1000. mg/L范围内呈线性关系,线性回归方程为△ip"(nA)=10.42 c(mg//L)-224.69(n=11,r=0.993),将该方法应用于透明质酸模拟样品的测定,结果令人满意.     

单扫描极谱法快速测定蛋白质的研究

在pH 4.7的HAc-NaAc缓冲溶液中,邻二氮菲与蛋白质相互作用,使邻二氮菲在-0.99 V(vs.SCE)处的还原峰电流下降,电流降低值与所加的蛋白质(人血清白蛋白、牛血清白蛋白、溶菌酶)的量在一定范围内呈线性关系,线性范围分别为2.0~22 mg/L,2.0~20 mg/L和4.0~26 mg/L;检测限分别为1.0 mg/L,1.0 mg/L,2.0mg/L。运用该方法测定了人血清中白蛋白的含量,结果满意。     

环丙沙星-锌（Ⅱ）的配合物吸附波

用极谱和伏安法研究了环丙沙星与锌离子配合物的性质及其电化学行为。在0．2moL／L的KCl-BR缓冲溶液中（pH=8．0）,环丙沙星与锌离子产生灵敏的配合吸附波,峰电位Ep=-1．22V。锌离子与环丙沙星的配合比为1：2。实验表明该峰为不可逆的还原波。峰电流与环丙沙星的浓度存在良好的线性关系,线性范围为3．65×10^-7 moL／L～1．95×10^-5moL／L,相关系数r=0．9995,检出限2．4×10^-7moL／L。可用于片剂及滴眼液中环丙沙星的测定。     

单扫描示波极谱法检测哌拉西林钠

在0.66mol／L KCl(pH=6.70)的底液中,哌拉西林钠在汞电极上有一灵敏的导数还原峰,其峰电位Ep=-1.23V(vs.SCE).峰电流与哌拉西林钠的浓度在8.0×10-6至7.0×10-8mol／L范围内呈良好线性关系(r=0.9992),检出限为4.5×10-8mol／L,该法应用于注射用哌拉西林钠中哌拉西林钠含量的测定,结果令人满意。实验表明,该体系为一具有吸附性的不可逆过程。     

Nafion修饰分散铋电极线性扫描伏安法测定肝素钠含量

利用循环伏安法(CV)、线性扫描伏安法(LSV)研究了肝素钠在铋膜玻碳电极上的电化学行为。在pH 5.4的B-R缓冲溶液中,肝素钠在-0.79 V左右处产生一灵敏的不可逆氧化峰,并对其电化学检测条件进行了优化,在选定的最佳条件下,峰电流与肝素钠浓度在0.4~2.0 mg/L范围与其峰高有良好的线性关系。回归方程为Ip=11.12 80.91c(mg/L),r=0.991,检测限为0.08 mg/L。考察了干扰物质的影响,据此建立了一种快速、简便测定肝素钠的方法。将本方法应用于肝素钠样品的测定,结果令人满意。     

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。