天然产物分离新技术

对天然产物的提取方法和分离精制方法进行了综述。对天然产物的提取方法如双水相萃取、超l临界萃取、微波提取、超声波提取和液膜提取等进行了论述，并对分子精馏、大孔吸附树脂、凝胶色谱和分子印迹等技术在天然产物分离精制上的应用进行了介绍。对各种方法的特点和不足进行了比较。     

超声技术在中药化学成分提取中的研究进展

综述了超声波技术在天然产物活性物质提取中的应用情况,讨论超声波在中药有效成分提取中的作用原及其频率、强度、时间、占空比对中药有效成分提取率的影响。得出了超声波技术提取中药有效成分有着提取率高、速度快、操作简便等优点及超声波提取中应注意的问题。     

天然产物有效成分提取分离制备方法研究进展

随着天然产物有效成分药用和食用疗效研究不断深入,有关其提取分离方法的相关研究日益受到重视。但传统的提取分离方法因步骤繁琐、有效成分损失多、制备效率低,逐渐被一些新型提取分离技术取代。综述了超声波辅助提取、超临界流体萃取、加速溶剂萃取、微波辅助提取等分离技术以及大孔吸附树脂、制备型高效液相色谱和高速逆流色谱等纯化制备技术在天然产物有效成分提取分离中的应用。对它们的应用前景和发展方向进行了展望。     

超声波辅助萃取天然植物香料研究进展

超声波辅助萃取技术近年已经在天然植物香料萃取方面得到越来越广泛的应用。对超声波（溶剂法）萃取、超声强化超临界CO2萃取和超声-微波协同萃取在天然植物香料提取方面的最新应用及研究进展进行了总结,同时对超声波辅助萃取天然植物香料前景进行了展望。     

天然有机化合物提取与分离技术的研究和应用进展

对天然有机化合物的提取和分离技术进行了综述.对天然有机化合物的提取方法如超临界流体萃取、超声波提取、半仿生提取、酶法提取、微波辅助提取、固相萃取、固相微萃取进行了论述,并对大孔树脂吸附分离、高速逆流色谱分离、膜分离、高速离心分离、分子蒸馏、双水相萃取在天然有机化合物分离上的应用进行了详细论述.     

超临界CO2萃取技术在天然产物提取中的应用

文章论述了国内外超临界CO2萃取技术进行天然产物提取的开发利用现状、与传统提取方法相比具有的优越性、以及在现代工业生产中的应用现状和前景,并通过实验考察了超临界CO2萃取技术从万寿菊中提取叶黄素的工艺条件,结果表明在提取时间和叶黄素提取量上都优于传统溶剂提取法.最后对超临界CO2萃取技术应用于天然产物提取的前景进行了展望.     

分子蒸馏技术在天然产物提取分离中的应用

分子蒸馏技术是在高真空下进行的一种特殊的蒸馏技术,由于能很大程度上降低高沸点物料的分离成本,保护热敏性物质的品质而备受关注。在天然产物研究领域中,该技术主要用于具有生物活性物质的提取、分离和精制。但随着研究的深入,其应用在天然产物中也存在一些问题。为此,本文根据分子蒸馏技术的原理及特点,对该技术在天然产物提取分离中的应用以及存在的问题做了较全面的介绍。     

植物精油提取方法研究进展综述

现今,植物精油提取方法很多。植物精油是植物体的次生代谢产物,化学组成较为复杂。下面的研究主要针对国内外对天然植物精油提取的传统提取方法及超临界CO_2萃取法、连续亚临界萃取、微波萃取、微胶囊双水相萃取、超声波萃取、分子蒸馏等最新技术的提取方法及特点进行概括。重点对各种精油提取技术的优缺点及实际应用中的发展前景进行归纳。     

纤维素酶在天然产物提取中的应用研究

酶解法广泛应用于天然产物的提取,具有条件温和、易于控制、有效成分破坏少等优点。文章对纤维素酶的结构、降解机制及其在天然产物提取中的应用进行了综述,并展望了该技术今后的发展趋势及应用前景。     

橄榄苦苷提取工艺的研究进展

对橄榄苦苷的提取工艺进行了综述,并从提取时间、提取效率、能耗等方面对不同方法进行了分析比较,认为超声波与低温减压的组合是一种当前适合工业化生产,并且操作简易、效率高、能耗低的提取方法;另外,笔者认为未来天然产物提取装置可以与先进的分析技术HPLC、GC-MS等仪器直接联用以实现在线分析检测,不仅可提高分析检测的速度,也可以控制产品的质量,这也是未来研究天然产物提取分离的一种发展趋势。     

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。