N-辛基-O-聚乙二醇壳聚糖衍生物的制备与表征

以自然界富有的天然壳聚糖为原料,在其分子结构的2位—NH2上引入部分疏水性辛基,并对其余的—NH2进行有效保护;然后在3,6位的—OH上引入亲水性聚乙二醇基团,合成了具有两亲性的N-辛基-O-聚乙二醇壳聚糖衍生物。通过FTIR,1HNMR和元素分析对衍生物的分子结构和N-位、O-位取代度进行了表征。该壳聚糖衍生物具有两亲性,水溶性好,且分子结构中保留了可用于后续交联反应的活性—NH2,在制备两亲性壳聚糖微球型药物载体领域具有潜在的应用价值。     

两亲性壳聚糖的研究进展

壳聚糖因其具有优良的生物相溶性和生物降解性且安全无毒,而成为近年来国内外研究热点。但由于其结构特点导致壳聚糖的溶解性较差(酸性溶液除外),严重限制了壳聚糖在医药、生物等领域的应用。介绍了壳聚糖缓释体系在中医药领域的研究进展,和两亲性壳聚糖化学改性的常见方法及其应用,得到两亲性壳聚糖衍生物,引入更多的功能性基团从而改善壳聚糖的性质,拓宽了其应用范围。     

N-亚甲基壳聚糖亚磷酸酯的合成和性质

为了得到一种新型低密度脂蛋白吸附剂,将具有聚阳离子性质的壳聚糖(CTS)通过改性制备了一种聚阴离子衍生物.利用Mannich反应原理,在壳聚糖的氨基上引入了亚磷酸酯基,制备了新型阴离子型壳聚糖衍生物N-3P-甲基壳聚糖亚磷酸酯(NMCP).对衍生物的化学结构和性质通过FTIR、XRD和动态接触仪进行了表征,并研究了CTS和NMCP对脂蛋白的吸附性能.     

低窄壳糖两亲分子的合成及表面活性

以窄的相对分子质量(简称分子量,下同)分布的低聚壳聚糖(简称为低窄壳糖;LNCS20,聚合度DP=20;分子量分布指数M w/M n=1.20)为原料,制备了两亲性衍生物N-琥珀酰化-N'-癸烷基低窄壳糖(SDLNCS20)。通过FTIR和1HNMR对SDLNCS20结构进行了表征,并对其溶解性、乳化性和润湿性能进行了测试,通过表面张力和荧光光谱法对其表面活性和临界胶束浓度(CMC)进行了研究。结果表明,LNCS20氨基位上成功引入了亲水性琥珀酸酐残基和亲油性长链烷基,SDLNCS20的CMC值为0.355 g/L,对应的表面张力为30.01 mN/m,具有良好的水溶性和乳化性能。     

降胆固醇类聚合物吸附剂的研究进展

综述了用于降低胆固醇的聚合物吸附剂的最新研究动态,重点介绍了传统吸附剂考来烯胺和考来替泊;合成大分子吸附剂Cholestagel、SK&F 97426-A、DMP504等;天然大分子衍生物吸附剂葡聚糖季铵阳离子凝胶、壳聚糖衍生物等;以及其他新型吸附剂生物轭合物、两亲性嵌段共聚物等.在这些新型吸附剂的开发过程中,通过分子结构设计在骨架分子上引入活性基团,以期借助离子交换、静电引力、氢键及疏水键相互作用等与胆酸或胆固醇相结合,提高其吸附能力和选择性.     

N-羧乙基壳聚糖对重金属汞离子絮凝效果的研究

N-羧乙基壳聚糖(NCECS)分子结构中既有氨基又有羧基,是一种两性的壳聚糖衍生物,具有生物相容性、生物降解性、无毒性等特点.合成了一种部分取代的NCECS,用傅里叶红外光谱(FTIR)、元素分析仪对其结构及取代度进行了表征,重点研究了NCECS浓度、絮凝时间、pH等因素对重金属Hg2+的去除率的影响,并探讨了NCEC...     

聚乙二醇接枝壳聚糖对涤纶织物性能的影响

以壳聚糖为原料,通过邻苯二甲酸酐封闭2位氨基,利用三聚氰氯将壳聚糖的6位羟基引入聚乙二醇(PEG2000)链上,得到水溶性较好的壳聚糖衍生物(TCSO-PEG2000)。用TCSO-PEG2000整理剂对涤纶织物进行处理,采用红外光谱和扫描电镜对整理剂及涤纶织物进行表征分析,研究整理剂的用量、焙烘时间、焙烘温度等对涤纶织物的强力、透气性、亲水性、抗静电等性能的影响。结果表明:在整理剂质量浓度为8 g/L、焙烘时间为5 min、焙烘温度为120℃时,涤纶织物具有较好的力学性能、亲水性能及抗静电性能。     

壳聚糖衍生物在工业循环冷却水处理中的应用研究进展

详细介绍了壳聚糖衍生物在工业循环冷却水中作为阻垢缓蚀剂方面的研究进展,主要从壳聚糖衍生物的合成及其对阻碳酸钙垢、硫酸钙垢和硫酸钡垢性能的影响,以及在酸性溶液、天然海水和模拟海水等介质中对金属腐蚀的抑制作用等方面进行阐述。开发成本更低、效果更好的壳聚糖衍生物产品,通过在壳聚糖分子结构中引入功能性官能团来提高产品性能,与其他水处理药剂进行复配研究是壳聚糖衍生物在工业水处理领域未来发展的方向。     

季铵化壳聚糖衍生物的合成与表征

以壳聚糖为原料,首先进行壳聚糖的季铵化,随后连接长链饱和脂肪酸,选择癸酸、月桂酸、肉豆蔻酸、棕榈酸和硬脂酸来连接季铵化壳聚糖,使其具有两亲性以成为药物传送的载体。设计并合成了两亲性的季铵化壳聚糖衍生物,并使用红外光谱、核磁共振氢谱和核磁共振碳谱等方法对其化学结构进行表征。实验发现,季铵化程度对脂肪酸连接反应影响较大,分别选择了一步和两步季铵化的壳聚糖与脂肪酸进行反应,以探讨其中的关系。     

降解壳聚糖季铵盐的制备及其在亚麻染色中的应用

降解壳聚糖季铵盐是将降解壳聚糖的氨基通过引入基团转换成季铵盐或者把一个低分子季铵盐接到氨基上而得到的一类降解壳聚糖衍生物。降解壳聚糖季铵盐在亚麻织物染色中的应用研究表明其具有一定的助染作用。国外对壳聚糖季铵盐的合成已有报道,如1985年国外报道了碘化壳聚糖季铵盐的合成方法,但得到的碘化N-三甲基壳聚糖季铵盐是不溶于水的。     

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.     

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.     

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。     

ICP-MS法测定地球化学样品中As、Cr、Ge、V等18种微量痕量元素的研究

建立了测定地球化学样品中包括As、Cr、Ge、V等18种微量、痕量元素的ICP-MS方法。地化试样用HF-HNO3混酸分解后,以1 1 HNO3溶解干渣。由于制样不使用盐酸,避免了Cl对As、Cr、Ge、V的质谱干扰。用国家一级地球化学标准物质GBW 07309制备溶液优化仪器工作参数,并用于校准。方法测定限(6s)为:0.007~6.4μg/g,精密度(RSD%,n=12)为:29%~9.4%,经过国家一级地球化学标准物质的分析验证,结果与标准值吻合。方法已应用于国土资源调查的试样分析。