低共熔溶剂中合成5-亚苄基巴比妥酸衍生物

低共熔溶剂是一种新型绿色溶剂,可以作为大多数有机反应的溶剂,同时也可起促进作用。室温搅拌下,在尿素-氯化胆碱体系的低共熔溶剂中,通过芳香醛和巴比妥酸反应合成5-亚苄基巴比妥酸,实验结果表明,在室温无催化剂条件下,尿素-氯化胆碱低共熔溶剂用量为1.5mL,芳香醛与巴比妥酸的物质的量比为1∶1.1,反应时间2h,5-亚苄基巴比妥酸衍生物3c产率可达92.6%。得到的产物用熔点、红外和核磁进行了表征。     

氯化胆碱-尿素离子液体合成及性能研究

以氯化胆碱、尿素为原料合成氯化胆碱-尿素低共融体系离子液体,考察原料配比、反应温度、反应时间对离子液体合成的影响。最佳合成条件为:n(尿素)∶n(氯化胆碱)=2∶1,反应温度为80℃,反应时间为90 min。利用傅里叶变换红外光谱仪、紫外可见分光光度计、旋转黏度计以及溶血实验对合成产物进行检测。合成产物的红外光谱图与氯化胆碱-尿素离子液体谱图一致;由紫外可见分光光度计检测可知,氯化胆碱-尿素低共融体系合成过程中透过率随时间的延长而增大,最终趋于稳定;合成的离子液体的黏度随温度的升高而减小;溶血实验结果表明,合成的离子液体不会发生溶血现象,具有良好的生物相容性。利用合成的离子液体溶解牛皮胶原,通过分析溶解产物的红外光谱可知,离子液体能够直接对牛皮中胶原进行物理溶解。     

绿色低共熔溶剂提取野菊花中黄酮类化合物

研究氯化胆碱低共熔溶剂(DES)提取野菊花中的总黄酮、总槲皮素和槲皮苷.首先,合成了4种性能优异的DES,并对其物理性质进行表征.其次,以提取效果最好的氯化胆碱/尿素DES为溶剂,通过改变单一变量优化提取效果,在含水量30％、提取时间45 min、固液比1:50(g:mL,下同)、提取温度60℃的条件下,总黄酮、总槲皮...     

低共熔溶剂中β-吲哚衍生物的绿色合成

在低共熔溶剂氯化胆碱/尿素中,芳香醛、吲哚和丙二腈三组分通过"一锅法"反应合成了10个2-[(3-吲哚基)-芳甲基]丙二腈衍生物(β-吲哚衍生物),反应条件温和,产率达66%~94%。此外,还讨论了反应速度与取代基的关系,探讨了氯化胆碱/尿素的催化机理。催化剂回收利用5次仍然保持较高的催化活性,并运用1HNMR、13CNMR技术手段确定了产物的结构。     

响应面法优化废旧毛涤粘面料溶解工艺

采用磷酸/多聚磷酸混酸溶剂体系对废旧毛涤粘混纺面料中的粘胶进行溶解,混酸溶剂体系溶解粘胶的最佳工艺为P_2O_5质量分数74%,固含质量分数14%,温度25℃。采用由尿素、亚硫酸氢钠和十二烷基硫酸钠(SDS)组成的还原C体系对混纺面料中的羊毛纤维进行溶解,通过响应面法探讨了尿素浓度、亚硫酸氢钠浓度、SDS浓度、时间等参数对羊毛溶解率和角蛋白提取率的影响,优化羊毛溶解工艺条件为:尿素400 g/L,亚硫酸氢钠40 g/L,SDS 20 g/L,时间6 h,浴比1∶20,p H为11;最优溶解方案下的羊毛溶解率和角蛋白的提取率分别是89.53%和49.32%。     

LTTMS混合物在乙醇-水体系分离中的应用

分别乙二醇和两种低共熔溶剂(氯化胆碱/乙二醇(摩尔比1∶2)、氯化胆碱/乙醇酸(摩尔比1∶3))为萃取剂,设计萃取精馏和隔壁塔萃取精馏流程,模拟分离乙醇和水形成的共沸体系。使用灵敏度分析对上述流程分别进行了参数优化。在优化的基础上,进行了年度费用(TAC)计算。结果表明:采用乙二醇和低共熔溶剂为萃取剂的萃取精馏和隔壁塔萃取精馏均能实现乙醇-水的分离;年度费用结果表明采用氯化胆碱/乙二醇(摩尔比1∶2)的隔壁塔萃取精馏费用最低,为最优工艺。     

羊绒纤维的还原法降解回收

为回收利用动物蛋白质纤维,采用TDO/尿素/SDS溶解体系对羊绒进行降解处理,然后提取其中的角蛋白以供纤维再生。实验中,调整体系中各成分浓度及pH值,以溶解率和提取率为测试指标,通过单因素分析和正交优化,确定提取角蛋白最优工艺。研究发现,影响溶解率、提取率各因素的主次顺序分别为:pH尿素浓度TDO浓度SDS浓度和pHTDO浓度尿素浓度SDS浓度,可获得78%的最优提取率,溶解率达92%,角蛋白分子量在46～100 kDa,有望进一步纺丝加工。     

羊毛角蛋白-聚乙烯醇再生纤维的结构性能表征

从废旧毛涤混纺面料中提取出羊毛角蛋白,配制角蛋白含量不同的3种纺丝液,通过静电纺丝方法得到羊毛角蛋白-聚乙烯醇(PVA)再生纤维。用扫描电镜观察、红外光谱分析及热学性能分析发现:3种羊毛角蛋白-PVA再生纤维膜中的纤维分布均匀、相互交叉,直径在230~260 nm左右;3种再生纤维的红外光谱都具有明显的角蛋白与PVA的特征;3种再生纤维膜的热稳定性差异不大。     

低共熔溶剂体系提取中药渣中肉桂醛

筛选适合的低共熔溶剂(DES)对中药渣疏水性功效成分进行高效提取对提高中药固废物的资源化利用效率有着重要的意义。采用微波辅助低共熔溶剂法对肉桂枝中药渣原料中的肉桂醛进行提取，考察低共熔溶剂类别、固液比、提取时间、摩尔比、提取温度等因素对肉桂醛提取率的影响。结果表明：氯化胆碱与乙二醇组成的DES体系中，在氯化胆碱与乙二醇摩尔比为1∶6、固液质量体积比1∶60、提取温度100℃、反应时间90 min的较优条件下肉桂醛的提取率可达到12.64 mg/g,相比传统甲醇提取法提取率增加了45.45%。中性DES相比酸性DES对功效成分的稳定性和提取效率都具有较佳的效果。氯化胆碱和乙二醇中性DES有益于中药渣功效成分的提取和纯化，具有较大的发展潜力。     

微波辅助低共熔溶剂高效提取油茶壳原花青素的工艺优化

氯化胆碱/草酸体系的低共熔溶剂作为提取溶剂,采用微波辐照萃取,分离油茶壳原花青素,研究微波功率、原料粒径、微波温度、微波时间、溶剂含水量和料液比对油茶壳原花青素提取量的影响。结果表明,油茶壳原花青素的最佳提取工艺参数。原料过200目筛而不过400目筛(平均粒径为53μm),溶剂含水量5%,料液比1∶20 (g/mL), 600 W的微波功率,35℃微波辐照提取60 min。在此优化条件下,油茶壳中原花青素的提取量为66.89 mg/g。     

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.     

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。     

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.     

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.     

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.     

基于ATRP法制备的触角状亲水性羟胺树脂的吸硼性能的研究

以大分子引发剂氯乙酰化聚苯乙烯微球(PS-acyl-Cl)经原子转移自由基聚合(ATRP)法引发丙烯酰胺(AM)和甲基丙烯酸缩水甘油酯(GMA)单体的共聚接枝,制得一种触角状亲水性环氧载体(PS-acyl-g-P(AM-co-GMA)),再经二乙醇胺(DEA)的环氧基开环胺化反应,得到一种含多个-NCH2CH2OH螯合配基的多齿-五元螯合环的触角状亲水性羟胺树脂(PS-acyl-g-P(AM-co-GMA)-DEA)。将此树脂用于硼吸附研究,结果表明,PS-acyl-g-P(AM-co-GMA)-DEA树脂对硼的吸附满足Langmuir方程,为单分子层吸附;饱和吸附量约为37.7 mg·g-1,且树脂5 min即可达到吸附平衡,与其它已报道的吸硼树脂相比,该树脂具有更高的吸附量和吸硼速率。吸附动力学研究表明,树脂吸附硼的过程主要由颗粒扩散过程控制。重复使用5次后该树脂的吸附量基本不变,解吸率均在90%以上,重复使用性能良好。