吡咯红Y-SDS-蛋白质体系的共振光散射光谱研究

在硫酸存在下,微量蛋白质的加入可使吡咯红Y-SDS体系弱的共振光散射信号得到极大的增强。在λ=364 nm处,光散射强度最大,并且光散射增强强度与蛋白质的质量浓度在一定范围内呈线性关系,由此建立了一种测定蛋白质的新的分析方法。对牛血清白蛋白(BSA)和人血清白蛋白(HSA)进行测定,其线性范围分别为0.15~3.6μg/mL和0.06~4.8μg/mL,检测限分别为21.0 ng/mL和12.0 ng/mL。该方法用于人血清样中蛋白总含量的测定,结果令人满意。     

苯妥英钠-Pb2＋体系共振散射光谱的研究与分析应用

在弱酸性介质中,苯妥英钠与硝酸铅结合形成的离子缔合物导致体系的共振散射强度急剧增强,并产生特征散射峰,最强散射峰位于488nm。在适宜的条件下,苯妥英钠浓度在1．25～32．5μg／mL范围内与体系散射强度的增加（△I）有良好的线性关系,方法的检出限为0．89μg／mL（30r）。本法用于药物制剂中苯妥英钠的含量测定,操作简便、快速,灵敏度高。     

共振散射光谱分析法测定纯净水中氯化物

在硝酸和Triton X-100余质中,氯化物能与硝酸银定量反应生成稳定的氯化银纳米微粒,存在共振散射效应。Cl^-的浓度在0．071～5．325μg／mL范围内与共振散射强度（IRS）成较好的线性关系。检出限为0．034μg／mL,用于纯净水中氯化物含量的测定,具有简单、快速、灵敏度高等特点,结果满意。     

偶氮胭脂红G结合共振光散射法测定人血清样品中的总蛋白

研究了在pH为2.5的BR缓冲酸性介质中,偶氮胭脂红G与牛血清白蛋白(BSA)、人血清白蛋白(HSA)、鸡蛋白蛋白(OVA)及免疫球蛋白(γ-IgG)等蛋白质作用产生共振光散射(RLS)增强信号,最大散射峰位于594nm处。在最佳实验条件下,增强RLS强度在594 nm处与蛋白质浓度呈线性关系,检出限在0.025~0.406μg/mL之间,生物体液中大部分常见物质均不产生干扰。该法应用于人血清样品测定,测定结果与考马斯亮蓝法一致。     

一种测定血清脂蛋白a的胶乳增强免疫共振散射法

在pH为7．2的Tris-HCI缓冲溶液中,脂蛋白（a）抗体胶乳液与脂蛋白（a）发生免疫反应并在胶乳E聚集,导致体系的共振散射强度增强,在波长为580mm处有较强的共振散射峰。在选定条件下,脂蛋白（a）浓度在0．06～1．40μg·mL。范围内与580am处的散射强度呈良好的线性关系,其回归方程为A1Rs=325．6p-17．8,相关系数为0．996,检出限为0．0063μg·mL^-1。用于血清中脂蛋白a测定,仪器简单,操作简便,选择性好,结果满意。     

盐酸阿霉素共振光散射法测定酵母RNA

pH 8.69条件下,酵母RNA的加入使盐酸阿霉素的共振光散射信号强烈增强,在322与558 nm处产生两个共振散射峰。研究表明,在322 nm波长处共振光散射强度与酵母RNA的浓度在0.02~20μg/mL范围内呈良好的线性关系,检出限为2.3 ng/mL。该方法用于样品中RNA的测定,结果令人满意,由此建立了一种选择性好、灵敏度高的RNA共振光散射分析方法。     

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.     

亚铁氰化铜共振散射法间接测定卡托普利

在酸性介质中,铁氰酸根离子被卡托普利还原成亚铁氰酸根离子后与硫酸铜反应生成亚铁氰化铜粒子而导致体系的共振光散射信号显著增强。在492 nm处增强的共振散射信号强度(ΔI_(RS))与卡托普利的浓度在0.05～1.40μg/mL范围内呈线性关系,据此建立了一种检测卡托普利含量的共振散射(RS)分析方法。线性回归方程为ΔI_(RS)=305.59+1962.8ρ(ρ,μg/mL),相关系数(R)为0.9960,检测限(3σ/k)为0.017μg/mL。该方法已成功用于卡托普利片剂的测定。     

[PbI4]2--CV体系共振瑞利光散射法测定痕量结晶紫

在硫酸介质中,Pb2+与过量I-形成配离子[PbI4]2-,[PbI4]2-能与结晶紫(CV+)阳离子形成电中性的离子缔合物,使体系的共振瑞利散射(RRS)增强,据此建立一种新的共振瑞利光散射法测定痕量结晶紫的新方法。在0.07 mol/L H2SO4、1.8×10-4mol/L Pb2+、过量I-及0.04%PVA等的存在条件下,RRS强度改变值(ΔI)与结晶紫的浓度在0.15～180μg/mL范围内呈良好的线性关系(r=0.998),方法检出限为0.08μg/mL,RSD<2.5%,样品加标回收率为86.4%～107.3%。新方法灵敏、操作简便,应用于鱼肉和鱼池水中痕量结晶紫的测定,结果满意。     

[PbI_4]~（2-）-CV体系共振瑞利光散射法测定痕量结晶紫

在硫酸介质中,Pb2＋与过量I-形成配离子[PbI4]2-,[PbI4]2-能与结晶紫（CV＋）阳离子形成电中性的离子缔合物,使体系的共振瑞利散射（RRS）增强,据此建立一种新的共振瑞利光散射法测定痕量结晶紫的新方法。在0.07 mol/L H2SO4、1.8×10-4mol/L Pb2＋、过量I-及0.04%PVA等的存在条件下,RRS强度改变值（ΔI）与结晶紫的浓度在0.15～180μg/mL范围内呈良好的线性关系（r=0.998）,方法检出限为0.08μg/mL,RSD〈2.5%,样品加标回收率为86.4%～107.3%。新方法灵敏、操作简便,应用于鱼肉和鱼池水中痕量结晶紫的测定,结果满意。     

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。