溶胶-凝胶法制备链霉素分子表面印迹聚合物及其性能表征

以四氢呋喃、乙醇和水的混合溶液(体积比6∶1∶1)为分散剂,3-氨基丙基三乙氧基硅烷和苯基三乙氧基硅烷为功能单体,正硅酸乙酯为交联剂,氨水为催化剂,通过溶胶-凝胶法在二氧化硅微球表面制备了分子印迹聚合物。用分子对接的方法初步分析了链霉素与功能单体和交联剂之间的相互作用,验证了它们形成氢键的可能性。活化时间会影响分子印迹微球的形貌。吸附实验表明,分子印迹微球比非印迹聚合物微球对链霉素具有更优越的吸附性能和选择性。     

结晶紫分子印迹微球的合成及其性能

以结晶紫(CV)为模板分子、α-甲基丙烯酸(MAA)为功能单体、二甲基丙烯酸乙二醇酯(EGDMA)为交联剂,采用沉淀聚合法合成结晶紫分子印迹微球。同时,考察合成过程中不同交联剂、模板分子与MAA的配比以及交联剂用量对微球性能的影响。结果表明:采用恒温水浴振荡法,以30 mL乙腈为溶剂,模板分子、功能单体和交联剂物质的量比为1∶4∶20,所制备的聚合物微球最大吸附量Q为39.1μmol/g,分离因子(α)和印迹效率因子(β)分别为3.76和3.18,对目标分子结晶紫具有良好的特异性识别和吸附能力。     

原花青素分子印迹聚合物的制备及其吸附性能研究

目的制备原花青素分子印迹聚合物,研究其吸附性能。方法以原花青素为目标分子,甲基丙烯酸(MAA)为功能单体,乙二醇二甲基丙烯酸酯(EGDMA)为交联剂,偶氮二异丁腈(AIBN)为引发剂合成分子印迹聚合物。研究结果表明吸附溶剂选择水溶液为最佳溶剂,吸附时间在120min时可达吸附平衡,分子印迹聚合物对原花青素分子的吸附性能和非分子印迹聚合物相比增加显著,且具有很高的选择性。结论分子印迹聚合物能选择性地吸附原花青素,结果满意。     

沉淀聚合法制备咖啡因分子印迹聚合物微球

以咖啡因为印迹分子,甲基丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂,偶氮二异丁腈为引发剂,采用沉淀聚合法在乙腈溶液中制备了针对咖啡因的分子印迹聚合物微球。对沉淀聚合中单体、引发剂、溶剂用量的比例关系进行探索,并利用平衡结合实验研究了聚合物对印迹分子的吸附性能,结果表明该印迹聚合物微球呈现出较好的结合能力。     

壬基酚磁性分子印迹聚合物的吸附性能评价

该文以壬基酚(NP)为模板,4-乙烯基吡啶(4-VPy)为功能单体,采用表面分子印迹技术成功制备磁性分子印迹聚合物(Fe_3O_4@SiO_2-MIPs),通过正交试验优化制备条件,考察了Fe_3O_4@SiO_2-MIPs的吸附选择性、吸附等温线、吸附动力学、可重复利用性及再生性。结果表明制备的磁性分子印迹聚合物易于实现固-液分离,最优制备条件为:磁性载体投加量为2 g,温度为65℃,预组装体∶交联剂为1∶2,时间为24 h。Fe_3O_4@SiO_2-MIPs对NP具有特异选择吸附性,吸附等温线符合Sips模型,且该印迹聚合物表现出高效快速的吸附动力学特征,采用二级动力学模型可很好地拟合吸附动力学过程。该功能性吸附材料具有很好的可重复利用性和再生性能。     

乳液聚合法合成水杨酸分子印迹聚合物微球

以水杨酸为模板分子,乙二醇二甲基丙烯酸酯为交联剂,采用乳液聚合法制备了水杨酸分子印迹聚合物微球（SMIP）,采用紫外差示光谱分析了模板分子与功能单体的相互作用,以荧光分光光度计为检测手段,讨论了不同功能单体、模板分子与功能单体的摩尔比、交联剂用量、洗脱液类型等对SMIP吸附性能的影响,并进一步考察了SMIP的形貌和粒径分布。研究结果表明,以丙烯酰胺为功能单体合成的SMIP表现出较好的吸附性能,印迹因子可达1.61,而且微球呈单分散性,平均粒径约60 nm。     

反相微乳液法制备磁性分子印迹聚合物微球

以二氯苯酚为模板分子、丙烯酰胺(AM)为功能单体、三羟甲基丙烷三丙烯酸酯(TRIM)为交联单体、Fe3O4为磁性组分,采用反相微乳液悬浮聚合法制备了磁性分子印迹聚合物微球(MMIPMs)。研究了吸附时间、温度、pH对吸附性能的影响,并考察了其重复利用性。结果表明,温度对二氯苯酚-MMIPMs吸附性能影响不大。底物溶液pH对MMIPMs的吸附性能有一定影响,吸附量随pH的升高而增大,当pH为7.0时,吸附量最大。MMIPMs具有良好的重复利用率。     

溶菌酶分子印迹聚乳酸微球的制备及吸附性能

以改性聚乳酸微球(MPLA)为载体,以γ-(2,3-环氧丙氧)丙基三甲氧基硅烷为功能单体,以四乙氧基硅烷为交联剂,采用溶胶凝胶方法制备了表面溶菌酶分子印迹改性聚乳酸微球(LZY-MIP-MPLA),采用红外、扫描电镜和粒径测定等方法对LZY-MIP-MPLA进行了表征,优化了制备条件。详细研究了LZY-MIP-MPLA对溶菌酶的吸附性能,考察了pH和NaCl对吸附性能的影响。结果显示,LZY-MIP-MPLA对溶菌酶的吸附能力明显大于非印迹改性聚乳酸微球(NIP-MPLA),达到吸附平衡的时间为200min左右。Scatchard方程的分析表明,印迹孔穴对模板分子的作用是不完全等价的,即存在两类不同的结合位点。LZY-MIP-MPLA对溶菌酶和牛血清白蛋白的分离因子为10.13,说明其对溶菌酶具有较好的选择吸附性能。     

单步种子溶胀法与二步种子溶胀法制备氯霉素分子印迹聚合物微球的比较

以聚苯乙烯乳液为种球、氯霉素为模板分子、甲基丙烯酸为功能单体、乙二醇二甲基丙烯酸酯为交联剂,采用单步种子溶胀法与二步种子溶胀法制备了单分散氯霉素分子印迹聚合物微球,用光学显微镜和扫描电镜对微球的形貌进行了表征,并用静态吸附实验考察了微球的吸附识别性能,结果表明,二步种子溶胀法制备的微球分散性、吸附识别性能最佳,平均粒径...     

香草醛分子印迹聚合物的制备及其性能研究

以香草醛为模板分子,二甲基丙烯酸乙二醇酯(EDMA)为交联剂,甲基丙烯酸(MAA)为功能单体,采用悬浮聚合法和本体聚合法制备了香草醛分子印迹聚合物。利用扫描电镜、平衡吸附实验、选择性吸附实验等,探讨了两种聚合方法制备出的分子印迹聚合物的性能。结果表明,悬浮聚合法制备的分子印迹聚合物粒径分布更均匀,选择吸附性能更好,更适用于分离材料。     

Sapindaceae,cyanolipids, and bugs

Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.     

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.     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.     

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.     

2008～2009年世界塑料工业进展

收集了2008年7月～2009年6月世界塑料工业的相关资料,介绍了2008～2009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、环氧树脂、不饱和聚酯树脂)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。