细胞固定化条件对紫草细胞生产紫草色素的影响

以海藻胶做包埋剂,研究了固化液构成、细胞包埋量和胞龄对紫草色素合成的影响。结果表明：固定化细胞合成紫草色素的合适固化液为含有０．１ｍｏｌ／ＬＣａＣｌ２的紫草色素生产培养基,该固化条件比较温和,并可长久保持固定化细胞活性;最适宜的细胞包埋质量分数为１０％２０％;用于细胞包埋的最佳细胞生长时间为１７ｄ。对紫草细胞固定化培养生产紫草色素过程的动力学特征进行了分析,建立了基质消耗和色素合成的动力学模型,并用该模型对实验数据进行了回归分析,实验数据与理论值之间具有比较令人满意的一致性     

超声波对新疆紫草悬浮培养细胞生长和紫草素合成的影响

探讨了超声波功率、超声波处理时间对新疆紫草细胞生长和紫草素合成的影响. 研究结果表明,超声波对悬浮培养的新疆紫草细胞生长有促进作用,低功率长时间或高功率短时间的超声处理对细胞生长比较有利. 在优化条件下(200 W超声处理1 min),培养结束时的生物量比对照提高61%. 超声波也可以提高新疆紫草悬浮培养细胞的紫草素含量和产量,接种后即进行超声波处理,超声波功率密度为39.9 mW/cm3、超声时间为3 min时,细胞紫草素含量和产量最高,达到2.72%和294 mg/L,分别比对照组提高了64%和135%. 超声波是通过提高细胞苯丙氨酸解氨酶的活力来强化紫草素的生物合成途径.     

一步法培养紫草细胞生产紫草宁工艺与机理研究

本文提出一步法培养生产紫草宁新工艺，将细胞生产和产物合成两阶段合二为一，免去了原两步法培养中细胞生长阶段后必须充分过滤、洗涤等操作．该工艺操作简单、生产率高、细胞可重复利用．培养的紫草于占细胞干重已达17．9％，色素产量最高达2．3g／L.一步法培养的细胞重复使用试验表明，再生细胞的色素含量与原细胞的色素含量相近，一步培养末期进行半连续培养是可行的．在固体培养中，以一步培养基取代M－9培养基，接种量小，收获时紫草宁占细胞干重可达IS．7％，色素产量为2．7g从．本文对紫草合成机理进行了分析，提出了新疆紫草细胞…     

紫草细胞悬浮培养的动力学

通过对紫草细胞进行悬浮培养,测定了培养基中碳源、氮源、磷酸盐等无机元素的变化;并分析了细胞结构性组分、细胞呼吸以及次生代谢产物紫草宁的合成情况,探索研究了细胞培养的内在规律,为建立结构化动力学模型奠定了基础。     

紫草素对变应性鼻炎大鼠TH细胞表型表达的调节作用

目的分析紫草素对变应性鼻炎(allergic rhinitis,AR)大鼠模型TH细胞免疫干预作用。方法用卵清蛋白(ovalbumin,OVA)局部滴鼻法建立大鼠AR模型,建模成功后紫草素干预组分别雾化吸入50、100、200、300μg/kg紫草素进行治疗,另设健康大鼠对照组和雾化吸入生理盐水模型组。观察分析干预组和模型组大鼠症状表现,病理学检查大鼠鼻黏膜变化,流式细胞术检测各组大鼠外周血TH细胞亚群水平,ELISA法检测外周血中IL-4、IL-12和IFNγ水平。结果大鼠经紫草素干预后,AR症状缓解,病理检查炎症表现轻;外周血中TH细胞亚群接近对照组(P0.05),但与模型组差异有统计学意义(P0.01);与模型组相比,IL-4表达水平降低,IL-12、IFNγ升高(P0.01),症状及细胞因子变化幅度与紫草素干预用量呈正相关。结论紫草素对AR大鼠模型中TH细胞的异常表达可起到纠正作用。     

微生物代谢的唯象关系和趋优行为

从非平衡态热力学出发 ,探讨了微生物细胞在追求最高生长速率的优化模式下的动力学行为 .将微生物的生长过程分成分解代谢和合成代谢两个过程 (黑箱模型 ) ,通过唯象关系优化生长速率 ,得到了最优的合成代谢和分解代谢速率与自由能变化的关系 .计算表明 ,该关系式可以描述实际体系的生长过程 .进一步将微生物的生长过程划分为分解代谢、合成代谢、ATP的生成与消耗 3个反应 ,得到了与黑箱模型同样的优化结果 ,并且探讨了总偶合度与单步反应偶合度的关系 .所用的方法可以用来分析细胞的趋优行为 .     

废纸造纸废水封闭循环系统高效菌动力学研究

研究了污染物高度累积的封闭循环废纸造纸废水中高效菌细胞的生长和反应基质消耗动力学方程。结果表明：在基质浓度低于0．26g／L时,微生物的生长速率同基质浓度正相关;随着微生物生长,基质浓度将降至动力学极限浓度,此时基质转化所产生的能量不能满足微生物生长、繁殖的需要,微生物的生长处于动态平衡。通过实验建立了动力学参数模型,对实际造纸废水生物处理工程应用有一定的指导意义。     

紫草细胞的双液相培养研究

通过选择液体石蜡为有机溶剂,对紫草细胞进行了双液相培养。了不同的有机相添加比例与加入时间对细胞生长,次生产物代谢的影响;分析了双液相培养的氧传递情况。     

紫草中活性成分的体外抗癌作用

对紫草中化学成分进行了抗癌活性研究。以顺氯氨铂(DDP)为阳性对照,通过形态学、MTT实验考察了从紫草中分离得到的7个化合物对人胃癌细胞MGC-803和人肝癌细胞BEL-7402的增殖抑制作用,并以抑制率和半数抑制浓度(IC50)为指标进行了评价。结果表明,7个化合物在体外对两株癌细胞有不同程度的抑制作用。去氧紫草素(Ⅰ)、β,β-二甲基丙烯酰紫草素(Ⅱ)、异丁酰紫草素(Ⅲ)、紫草素(Ⅳ)、甲基紫草素(Ⅴ)、β-谷甾醇(Ⅵ)、咖啡酸脂肪醇酯混合物(Ⅶ)和DDP对胃癌细胞MGC-803的IC50分别为:1.7、1.4、7.0、0.5、1.5、>100、>100和4.4μg/mL;对肝癌细胞BEL-7402的IC50分别为:1.5、1.3、34.0、1.3、1.4、>100、>100和7.6μg/mL。证明从紫草分离得到的萘醌类化合物(Ⅰ-Ⅴ)对人胃癌细胞MGC-803和人肝癌细胞BEL-7402的生长有较强的抑制作用,呈明显的剂量-药效依赖关系,其中化合物Ⅰ、Ⅱ、Ⅳ、Ⅴ的抗肿瘤活性远强于阳性药物DDP。化合物Ⅵ、Ⅶ则没有抑制这两株癌细胞的作用。     

包埋紫草细胞的海藻酸钙凝胶扩散性能

用非稳态法测定了充分搅拌条件下在未包埋紫草细胞和包埋紫草细胞的海藻酸钙凝胶珠粒体系内蔗糖溶液浓度的瞬间变化情况。结果表明，海藻酸钠浓度、氯化钙浓度和紫草细胞包埋量对蔗糖扩散有明显影响，有效扩散系数Ｄｅ随着海藻酸钠浓度、氯化钙浓度和紫草细胞包埋量的提高而下降．     

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.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008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、不饱和聚酯树脂、环氧树脂)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.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料,介绍了2005—2006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生产量以及各国塑料制品的进出口情况。作为对比,介绍了中国塑料的生产情况。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（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序,对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。