超声波辅助法提取朱砂七鞣质的工艺

通过单因素实验及正交实验对超声波辅助法提取朱砂七鞣质的工艺条件进行优化.确定最佳提取条件为:乙醇体积分数60%、料液比1∶15(g∶mL)、提取温度70℃、提取时间50 min,在此条件下提取2次,提取率为2.00%.超声波辅助法提取朱砂七鞣质工艺简单、省时、节能、提取率高.     

灯盏花素的提取与分离工艺优化研究

以灯盏乙素的提取率为指标,采用高效液相色谱法对灯盏乙素的含量进行测定,对灯盏花中灯盏花素的提取方法及工艺条件进行了优化.确定较优提取方法为超声波提取法,通过正交实验确定超声波提取法的最优工艺为:以10倍量的70%乙醇提取3次,每次60 min.此时,所得浸膏中灯盏乙素含量达到2.15%,提取率达到83.39%.超声波提取法是一种快速、简便、高效且稳定可行的灯盏花素提取方法.     

超声波强化提取荠菜中总生物碱的研究

采用超声波辅助提取法提取荠菜中总生物碱,考察了提取剂、料液比、提取时间、提取温度、超声波功率对生物碱提取率的影响.正交实验结果表明超声法的最佳提取条件为:乙醇体积分数为70%,料液比为1∶10,提取时间10 min,提取温度50℃,功率160 W.     

石蒜中石蒜碱的超声波提取研究

以野生石蒜为原料,以乙醇为提取剂,研究了石蒜中石蒜碱的超声波法提取工艺条件.通过单因素实验和正交实验确定超声波法提取石蒜中石蒜碱的最佳工艺条件为:超声波功率300 W、提取温度55℃、提取时间2.0h、料液比1∶ 5(g:mL)、提取2次,在此条件下,产率为0.464％、提取率为94.7％.与传统的溶剂法相比,超声波法...     

超声波协同丙醇-硫酸铵双水相体系提取灯盏花总黄酮的研究

将超声波技术和双水相萃取技术耦合用于提取灯盏花中总黄酮.通过单因素实验与正交实验得出最佳提取工艺条件为:丙醇体积分数50%、料液比1:30、超声提取15min,此时总黄酮平均得率为6.01%.将该方法与常规醇提法进行比较,结果表明两种方法提取率相当,但超声波-双水相提取法快速,简便,提取与分离能同时完成,具有明显的优势.     

超声波提取法对海燕总皂苷提取工艺的研究

采用超声波提取法从海燕中提取总皂苷。在考察单因素影响后,以溶剂浓度、提取时间、料液比、超声波功率及温度建立正交实验。比较超声波提取法与微波提取法和索氏提取法的提取率,结果表明:超声波提取法最优;影响超声波提取法提取率的主要因素为溶剂浓度与料液比,其次是温度和提取时间。超声波提取法提取海燕皂苷工艺的优选方案为:料液比1︰20,乙醇浓度85%,温度70℃,超声功率60 W,提取时间20 min。     

超声波法提取蓝莓叶总黄酮的工艺优化

以总黄酮提取率为考核指标,采用单因素实验与正交实验优化了超声波法提取蓝莓叶总黄酮的工艺条件,确定了最佳工艺条件为:提取溶剂为70%乙醇、固液比1∶35(g∶mL)、超声波功率210 W、提取时间40min,在此条件下,总黄酮平均提取率为8.0%,工艺稳定性良好。与常规提取方法相比,超声波法提取蓝莓叶总黄酮具有省时、经济、环保等优势。     

超声波法提取人参多糖的研究

人参根磨粉后,以蒸馏水为提取剂,用超声波法提取人参根中人参多糖,采用苯酚-硫酸比色法测定多糖含量.实验结果表明:超声波功率为200 W、超声波作用时间为30 min、m(人参粉):m(蒸馏水) =1:50、人参粉粒度为80目为最佳的操作条件,在此条件下提取的多糖质量分数比常规法提取3 h得到的多糖质量分数还高2.3%.     

不同提取方法对断肠草总生物碱提取率的影响

采用索氏回流、常规浸提、超声波3种方法提取断肠草总碱,考察粗提物的提取率。结果粗提物的提取率依次为1.22%、0.42%、1.57%。用超声波提取法比较了以95%乙醇、氯仿、甲醇为溶剂的提取率,结果依次为1.21%、1.57%、1.54%。通过正交实验,得到超声提取优化工艺条件:70℃条件下,超声提取30min×3次。表明以氯仿为溶剂,用超声波提取法提取断肠草总碱,提取率最高。     

超声波辅助半仿生法提取徽菊总黄酮工艺研究

根据半仿生法实验特点,采用pH2.2条件下,采用超声波-半仿生法提取徽菊总黄酮,并用正交实验对徽菊总黄酮半仿生法提取条件进行优化。实验表明,在pH2.2条件下,最佳提取条件为:乙醇浓度70%、固液比1:50,超声处理功率60%,超声处理40min,其溶出率为0.687±0.08%。实验表明超声波辅助半仿生法用来提取徽菊总黄酮具有可行性。     

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.     

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。     

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.     

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.