纤维素硫酸钠的批量制备及其NaCS-PDMDAAC微胶囊固定化黄色短杆菌培养过程研究

在非均相反应制备纤维素硫酸钠方法的基础上,通过增加液固比,引入搅拌,使体系的温度分布和浓度分布都得到很大改进,由此可以保证产品质量的均一性。用正交试验进行了500 mL反应器制备条件的摸索,并将其逐步放大到1 L、5 L反应器中进行,确立了5 L规模的生产工艺条件。通过对不同规模下制得的硫酸纤维素钠产品在理化性质、制备微胶囊及在微囊化培养等方面对比较,表明研制过程有利于合成出高质量的硫酸纤维素钠,用于制备微胶囊。用NaCS-PDMDAAC(聚二甲基二烯丙基氯化铵—硫酸纤维素钠)微胶囊固定化黄色短杆菌,考察了葡萄糖浓度、摇床转速对黄色短杆菌生长和代谢谷氨酸的影响,确定了一个较优培养条件。胶囊平均生产能力达15.29 g /(Lh)(对微胶囊)。微胶囊固定化黄色短杆菌连续培养12批后,仍具有良好的代谢谷氨酸性能。     

漂浮型微胶囊的制备及其性能评价

为了防止果酒储存过程中酒液表面菌膜的产生,用锐孔凝固浴法制备漂浮型海藻酸钠(sodium alginate,SA)/羟丙基甲基纤维素(hydroxypropyl methylcellulose,HPMC)微胶囊抑菌剂载体,使用乙基纤维素包膜,制备的微胶囊能成功漂浮于海红果酒中,对其漂浮性能进行研究,并采用正交试验对制备工艺条件进行了优化。结果表明:SA质量浓度为25 g/L,HPMC质量浓度为3.5 g/L,CaCl2溶液质量浓度为20 g/L时,包裹质量浓度30 g/L的乙基纤维素(ethyl cellulos,EC)(含无水乙醇)溶液所制备的微胶囊浮力值最大,密度值最小。用此方法制备的微胶囊能在海红果酒的表面漂浮5 d后漂浮率维持在50%。     

新型负载5-氨基水杨酸微胶囊的制备及其载药效果

采用锐孔/聚合法制备了平均粒径为1.89 mm、负载5-氨基水杨酸(5-ASA)的纤维素硫酸钠(NaCS)-壳聚糖微胶囊,采用Box-Behnken响应面法进行实验设计和分析,考察了内、外水相pH值和NaCS浓度、多聚磷酸钠(PPS)浓度对微胶囊载药量和包封率的影响. 结果表明,内水相pH值对负载5-ASA微胶囊的载药量和包封率起关键作用. 最佳制备条件为内水相pH 4.25,外水相pH 6.0,NaCS浓度14 g/L, PPS浓度5 g/L,该条件下所制微胶囊最大载药量为59.02%,最大包封率为89.96%..     

纤维素硫酸钠的制备方法及工艺条件的研究

采用了非均相反应制备 Ｎａ Ｃ Ｓ的方法,建立了工艺流程,并考察了不同游离硫酸浓度（４．５～５．５ｍ ｏｌ／ Ｌ）、不同反应温度（－ １０℃～０℃）下的纤维素转化率、 Ｎａ Ｃ Ｓ得率、取代度 Ｄ Ｓ和特性粘度 η１％ 随反应时间的变化关系。通过研究其动力学行为,确立了适合制作生物微胶囊用 Ｎａ Ｃ Ｓ的工艺条件。     

调酸介质对二甲戊灵微胶囊囊形及粒径的影响

[目的]优选出原位聚合法制备二甲戊灵微胶囊的较佳调酸介质,为二甲戊灵的微胶囊化提供一定的理论指导.[方法]以脲醛树脂为壁材采用原位聚合法制备了二甲戊灵微胶囊,研究了不同调酸介质对二甲戊灵微胶囊囊形及粒径的影响.[结果]5％盐酸溶液作为调酸介质形成的微胶囊囊形粗糙,产生粘连,粒径分布较宽;5％硝酸铵溶液、5％硫酸氢铵溶液作为调酸介质形成的微胶囊囊形松散,容易破裂,产生粘连,粒径分布较窄;5％氯化铵溶液作为调酸介质形的微胶囊囊形光滑致密且坚固,粒径分布较窄.[结论]调酸介质对原位聚合法制备的微胶囊囊形及粒径影响很大,选择合适的调酸介质能获得囊形致密、粒径分布窄的微胶囊.     

溶剂蒸发法制备高效氯氟氰菊酯微胶囊及其性能表征

针对高效氯氟氰菊酯使用过程中对人体皮肤的刺激性以及对水生生物的高毒性,以乙基纤维素为壁材,二氯甲烷为溶剂,通过设计L9（34）正交试验,采用溶剂蒸发法制备高效氯氟氰菊酯微胶囊,同时对微胶囊的理化性质和缓释特性进行表征。根据微胶囊平均粒径和未包封率的综合评分确定最佳制备工艺为：25%二氯甲烷,0.75%乙基纤维素,2%乳化剂,剪切8 min。扫描电子显微镜观察发现,所制微胶囊具有粒径大小均匀,表面光滑等特性;红外光谱图表明,高效氯氟氰菊酯被乙基纤维素包埋;释放特性曲线也表明微胶囊具有较好的缓释性能。该工艺操作简单,制备周期短,成囊性好,可为农药微胶囊的制备提供有效途径。     

半胱氨酸盐酸盐-乙基纤维素微胶囊的制备研究

选用半胱氨酸盐酸盐作为芯材,乙基纤维素作为壁材,采用有机溶剂蒸发技术制备微胶囊。通过单因素实验和正交分析得到最佳实验条件:壁材浓度为1%,海藻酸钠保护液浓度为0.5%,乙酸乙酯做溶剂,油水相比为5∶1,搅拌速度为1000 r/min,时间为2 h时得到的微胶囊的包埋率最高,粒径最小,分布最均匀。     

金纳米微粒修饰几丁聚糖微胶囊新方法

制备了金-海藻酸钙-几丁聚糖微胶囊,提出了修饰用于蛋白质药物靶向传输的多糖载体-几丁聚糖的新方法,该方法通过在几丁聚糖微胶囊表面结合金的纳米微粒使微胶囊表面结构发生变化,从而改变微胶囊的性质,这种修饰方法目前未见报道.文中对制备条件进行了优化,并对金-海藻酸钙-几丁聚糖微胶囊的粒径分布进行了表征.文中选择在pH值为5时反应2 h,制得的柠檬酸体系和丙烯酸体系的金-海藻酸钙.几丁聚糖微胶囊的平均直径分别为216.686um和196.850um.     

溶剂蒸发法制备高效氯氟氰菊酯微胶囊及性能

以乙基纤维素为壁材、二氯甲烷为溶剂,采用溶剂蒸发法制备了高效氯氟氰菊酯微胶囊。通过单因素实验考察了溶剂质量分数、壁材质量分数、乳化剂质量分数和剪切时间对微胶囊平均粒径的影响,通过以微胶囊平均粒径和未包封率作为评价指标的正交实验L9(34)优选了最佳工艺,并通过SEM、FTIR和HPLC对微胶囊的外观形貌、包覆效果和释放性能进行了表征。结果表明:随着溶剂质量分数增大,微胶囊平均粒径先减小后增大,w(溶剂)=25%时,平均粒径最小。随着壁材质量分数增大,微胶囊平均粒径增大。随着乳化剂质量分数增大,微胶囊平均粒径逐渐减小。固定剪切速率,微胶囊平均粒径随着剪切时间增加而减小。以w(二氯甲烷)=25%、w(乙基纤维素)=0.75%、w(乳化剂)[m(Tween80)∶m(Span20)=5∶1]=2%、剪切时间为8 min的工艺条件下得到的微胶囊外观光滑,形态规则,粒径较小(约19.2μm)且均匀,包封率高达82.8%,且具有较好的缓释性能。     

壳聚糖/明胶抗菌微胶囊的制备及其应用

为了制备用于棉织物天然抗菌整理剂,以绿苋、龙葵和黄柏的复配提取物为芯材,壳聚糖-明胶为壁材,采用复凝聚法制备抗菌微胶囊。研究了乳化剂含量、剪切速度、pH对微胶囊的外观形态及尺寸的影响;借助扫描电子显微镜、傅里叶红外光谱仪等对样品进行表征;将抗菌微胶囊用于棉织物的整理并测试其抗菌性能。结果表明：初乳中乳化剂质量分数为5%、剪切速度为8000r/min、pH为5.7为最佳制备条件,制得的微胶囊尺寸分布在1480～3580nm且热稳定性良好;当微胶囊质量浓度为25g/L,黏合剂质量分数为5%,热烘温度为40℃,整理试样对金黄色葡萄球菌和大肠杆菌的抑菌率分别为89.30%和81.43%,且抑菌效果持久。     

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。