反溶剂重结晶法制备青蒿素超细粉体

采用反溶剂重结晶法进行了青蒿素超细粉体的制备研究。以乙醇为溶剂,水为反溶剂,系统考察了药用辅料类型、反溶剂溶剂体积比、药物溶液浓度和混合强度对产品颗粒形貌和大小的影响。结果表明,辅料羟丙甲纤维素(HPMC)与聚乙烯吡咯烷酮 (PVP)联用可有效控制颗粒形貌,反溶剂溶剂体积比为20,青蒿素乙醇溶液浓度为20 mg·ml^-1,搅拌转速为8000 r·min^-1时,浆料中可得到平均短径0.84 μm、长径3 μm的针状颗粒,此浆料经喷雾干燥可得到粒径为2～3 μm的类球形粉体颗粒。进一步采用红外光谱、X射线衍射、差热分析、比表面积测试对原料药及产品的特性进行了表征,结果显示,青蒿素经反溶剂重结晶过程与辅料HPMC间产生一定的氢键作用,超细粉体产品的结晶度及熔点降低,比表面积增至原料药的26.4倍。体外溶出测试结果表明,青蒿素超细粉体的溶出速率远优于原料药,超细药物粉体15 min即可溶出88.3%,而同期原料药的溶出度仅为2.1%。     

亚临界水耦合冷冻干燥法制备芹菜素纳米分散体

在溶剂(亚临界水)-反溶剂(去离子水)体系下，利用溶剂反溶剂沉淀耦合冷冻干燥法，对芹菜素原料药进行了纳米化及改性，制备出了超细芹菜素颗粒及其水相分散体。系统地探究了反溶剂温度、亚临界水温度、反应压力、表面活性剂种类与浓度对造粒过程产生的影响，并通过扫描电子显微镜(SEM)、红外吸收光谱(FTIR)、X射线衍射 (XRD)、质谱分析(MS)等手段对原料药和产物进行了对比分析。结果表明，当反溶剂温度为0℃，亚临界水温度为160℃、反应压力为5 MPa、表面活性剂γ-环糊精的质量分数为5%时，可得到粒径在20~30 nm范围内，分布均匀，稳定程度较高且具有较低结晶度的纳米颗粒。本文报道的芹菜素纳米颗粒制备方法，全程无有机溶剂参与，易于生物医用推广，为基于芹菜素的口服药物设计与开发提供了参考。     

Span类表面活性剂对CL-20重结晶的影响

采用溶剂-非溶剂法重结晶CL-20,研究了溶剂-非溶剂体系中表面活性剂对CL-20晶体形貌的影响。用激光粒度仪、光学显微镜、红外光谱仪对重结晶CL-20的颗粒分布、形貌、晶型进行表征。结果表明,表面活性剂的种类、含量对CL-20的晶体形貌的影响较大,在以乙酸乙酯为溶剂、三氯甲烷为非溶剂、温度20℃、非溶剂稀释速度0.2~0.25mL/min、搅拌速度100r/min的转晶体系中,添加Span60使CL-20晶体颗粒生长形状趋近球形,表面光滑,颗粒均匀。     

HNS微晶形貌控制研究

采用溶剂-非溶剂法重结晶细化2,2',4,4',6,6'-六硝基(HNS),研究了不同非溶剂温度、搅拌速度、表面活性剂和洗涤方式等因素在重结晶细化过程中对HNS微晶形貌的影响,并结合晶体生长理论分析了各因素的影响机理.结果表明,选取非溶剂温度0 ℃、搅拌速度300 r/min,加表面活性剂羧甲基纤维素钠,用水洗涤,可得到粒度均匀,表面光滑的超细HNS晶体.     

超细酞菁蓝微粒的制备及其电泳性能的研究

实验采用反溶剂重结晶方法制备超细酞菁蓝(CuPc)颗粒,在重结晶过程中加入了不同类型的表面活性剂对酞菁蓝原料进行改性.用红外光谱(FT-IR)表征了重结晶粒子的表面组成,并通过扫描电镜(SEM)与激光粒度仪观察了粒子的形貌、分散情况及粒径分布.采用静态沉降法探讨了粒子在四氯乙烯中的稳定性,并利用电泳测试仪对粒子的电场响应特性进行测试.结果表明,重结晶过程中加入阴离子表面活剂十二烷基硫酸钠(SDS),所制得的粒子其分散稳定性和带电性最好.考察了SDS用量、反溶剂类型、反应温度对粒子稳定性和带电性的影响.得到的酞菁蓝最可几粒径为350 nm,沉降率22.3%,电场响应时间为6.1 s.     

降感RDX的制备及晶形控制

采用溶剂-非溶剂重结晶方法制备了降感RDX,研究了温度、溶剂、非溶剂、搅拌强度、表面活性剂和加料方式等工艺条件对双重结晶的影响.采用光学显微镜和扫描电镜分析了所得晶体的形貌,测定了其撞击感度.结果表明,采用最佳工艺条件:70℃,二甲基亚砜(DMSO)为溶剂,甲醇为非溶剂,糊精为表面活性剂,搅拌强度1 000 r/min,改善了RDX的晶貌和内部质量,降低了撞击感度.通过控制溶液的初始浓度可制得不同粒度的RDX,粒径为100～120 μm晶体的撞击感度比原料降低了34%.     

反溶剂重结晶法制备布地奈德超细颗粒及其肺部给药体外评价

利用反溶剂重结晶法对平喘药布地奈德进行了超细颗粒的制备研究.当以甲醇为溶剂,水为反溶剂时,分别考察了甲醇-水的体积比、混合强度和干燥方式对产品平均粒径和收率的影响.结果表明,当布地奈德甲醇溶液与水的体积比为1:7,搅拌转速高于5000r.min-1时,浆料中可得到平均长径3μm、短径2μm、厚度200 nm的椭圆形片状颗粒,并且一次收率为96.02%.将此布地奈德浆料通过真空干燥和喷雾干燥后.产品均可保持浆料中颗粒的大小与形貌,而经喷雾冷冻干燥后则变为10～20 μm左右的球形颗粒.FT-IR和XRD分析显示,与原料药和气流粉碎商品相比,反溶剂重结晶制得的布地奈德的化学结构与晶型均无改变.此外,经肺部给药体外评价,椭圆形片状颗粒具有最优的沉积分布,FPF值高达60%以上,分别比原料药和气流粉碎商品提高了9倍和1.5倍.     

超细琥珀酸舒马普坦的制备及其性能评价

利用反溶剂重结晶法进行琥珀酸舒马普坦微粉化研制,考察了溶液和反溶剂的体积比、结晶温度、搅拌速率和干燥方式等因素对产品粒径、形貌及性能的影响.采用扫描电镜(SEM)、红外光谱(FT-IR)和X射线衍射(XRD)对产品进行了表征.得到适宜的微粉化条件为溶液与反溶剂的体积比1:20,结晶温度4℃,搅拌速率2 000 r/min.利用体外模拟肺部沉积实验考察了不同干燥方式(真空干燥和喷雾干燥)对产品性能的影响.实验结果表明,真空干燥可以得到平均粒径约为1 μm的琥珀酸舒马普坦超微粉,喷雾干燥得到流动性好的薄片状产品,且喷雾干燥的产品体外肺部沉积效果明显优于经真空干燥制备的产品,有效部位沉积量高达(66.52±5.2)%,真空干燥产品仅有(16.54±6.4)%.     

重结晶提纯碳酸二苯酯的溶剂选择

为了寻找重结晶法提纯碳酸二苯酯(DPC)的适宜溶剂,文章对DPC重结晶溶剂的选择及影响DPC纯度的因素进行了研究。结果表明:乙醇是重结晶纯化DPC的适宜溶剂,DPC在乙醇中溶解度在5—15℃的区间内变化缓慢,重结晶中止温度在15℃左右,DPC的收率高于89.0%。乙醇和DPC比率(质量比)采用8∶5为重结晶DPC时的适宜比率。通过对重结晶溶剂的进一步研究,发现采用水-乙醇的混合溶剂作为重结晶溶剂时,可以明显提高DPC的收率。水的质量分数在25.0%—35.0%范围内时,DPC的收率大于93.0%,纯度高于99.6%。其纯度符合合成聚碳酸酯的要求。     

化学共沉淀法制备纳米氧化铝粉

以分析纯的硝酸铝和碳酸氢铵为主要原料，采用共沉淀法制备纳米氧化铝粉体，研究反应物的加料顺序和加料速度、表面活性剂种类、溶剂组成、晶种及前驱体的煅烧温度对产物的影响。采用X射线衍射仪分析粉体的物相组成，用谢乐公式计算晶粒尺寸，采用透射电子显微镜观测颗粒形貌。结果表明：原料的加料顺序对产物影响不明显，用PEG6000作表面活性剂，水和乙醇等体积混合液作溶剂，Al(NO₃)₃溶液直接倒入NH₄HCO₃溶液中制得前驱体，当煅烧温度为1135℃煅烧2 h时，制备了粒径为33 nm的α-Al₂O₃粉体，加入晶种后，煅烧温度可降低至1075℃。     

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.     

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.     

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。     

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.