Klebsiella sp. 601细菌漆酶的鉴定及性质

从森林树木根部土壤中分离得到一株具有2,6-二甲氧基酚(DMP)和2,2′-连氮基-双(3-乙基苯丙噻唑啉-6磺酸(ABTS)氧化活性的细菌.Cu2 、Ca2 、Mn2 、Fe2 和Mg2 可诱导细菌表达活性的胞质可溶性单体酶蛋白.该酶进行DMP或ABTS氧化时需要铜离子的协助,在pH5.0～7.5范围内氧化DMP,在pH4.0～4.5范围内氧化ABTS,但不能氧化酪氨酸.SDS-PAGE估测酶蛋白分子量大约为55 kD.经60℃处理4 h或pH10条件下透析20 h仍能保持酶活性.16S rDNA序列分析结合常规细菌形态学分析,表明该细菌属于克雷伯氏菌(Klebsiella)属,并命名为Klebsiella sp.601.这是首例报道Klebsiella细菌菌株具有漆酶活性.     

1，3-丙二醇脱氢酶一步纯化与杂化凝胶固定化的初步研究

转录表达来源于Klebsiella．pl,3-丙二醇脱氢酶（PDH）基因片段的E．coli工程菌,在5L发酵罐、30℃、pH值7．0、200r／min（微氧）条件下培养20h;发酵菌体经破碎分离后所得样品通过HisTrap HP柱亲和层析一步纯化得到电泳纯的PDH,纯化倍数为2．94倍,活性回收率为50％,经SDS-PAGE电泳鉴定获得一条清晰条带,表达蛋白亚基相对分子质量约为41kDa。用改进的溶胶-凝胶法（杂化凝胶）包埋纯化酶,考察正硅酸乙酯（TEOS）浓度、海藻酸盐（ALG）浓度、CaCl2浓度及ALG与TEOS体积比等因素对酶固定化效果的影响,结果表明,较优包埋条件为：ρ（TEOS）=20g／L,ρ（ALG）=30g／L,ρ（CaCl2）40g／L,V（ALG）：V（TEOS）=3：1;由此制备的PDH的ALG-SiO2杂化凝胶保藏60天后酶活仍保持80％,进行批次反应时,反应3批后酶活保持70．3％,反应第6批时酶活剩余29.8％。     

TBA-Pb2＋-hemin模拟酶催化显色法测定水中痕量铅

在pH 7.5的Tris-HC1缓冲液中,凝血酶适体（TBA）与Pb2＋形成复合物,再与氯化血红素（hemin）配位结合,形成辣根过氧化物模拟酶,能催化H2O2氧化2,2＇-连氮-双（3-乙基苯并噻唑-6-磺酸）（ABTS）,生成蓝绿色自由基产物,导致体系在415 nm处吸光度值增加,且在1.07 × 10-10～6.01 ×l0-7 mol/L范围内△A值与pb2浓度有良好线性关系,其回归方程为△A=0.409 c（×10-9 mol/L）＋40.7,相关系数r=0.996 6,检出限为3.21×10-11 mol/L,相对标准偏差在0.67％～3.45％.用于环境水样测定,回收率在98.2％～102.7％.该方法特异性好、灵敏度高.     

富含铬渣的碱性土壤中六价铬原地还原

在研究美国新泽西州铬渣区时发现：含铬物质下面所含0．5、4英尺厚的腐烂植物层（当地称为“meadowmat”——“草垫”）起着阻挡Cr^6＋迁移的天然屏障作用。紧靠草垫下的砂层中地下水含铬低甚至检不出。由于细菌和有机物的共同作用，草垫处于高还原条件。由于草垫这种将Cr^6＋还原为Cr^3＋的能力，从生物活性上以实验室规模的柱式试验，研究了将铬渣区Cr^6＋原地还原为Cr^3＋的可行性。典型铬渣有着高pH（超过12），总铬浓度高达70000mg／kg。实验结果证实，加入无机酸（将pH降到7．0～9．5间）和富含细菌的有机物（新鲜粪肥），可使Cr^6＋原地还原为低毒性、难迁移的Cr^3＋。经8个月后，孔隙水中Cr^6＋由800mg／L下降至0．05mg／L。此值低于美国环保局饮水中铬规定的最大值（MCL）0．1mg／L。柱试11个月后，固相中Cr^6＋浓度由约2000mg／kg降至小于10mg/kg，而总铬浓度保持未变。柱试后的固体用毒性浸取步骤（TCLP）浸取，符合小于5mg／L的规定值，而未处理样品的TCLP浸取浓度大于40mg／L。本研究证明了通过调节pH7．0-9．5并与富含细菌的有机物混合，可将Cr^6＋污染的土壤原地还原。     

Fe~0/Electro-Fenton对邻苯二甲酸二甲酯的降解研究

以纳米零价铁（Fe0）为铁源的Electro-Fenton（Fe0/E-Fenton）对邻苯二甲酸二甲酯（DMP）的降解进行了研究。与Fe2＋/E-Fenton体系相比较,Fe0/E-Fenton对DMP的降解效果更好。Fe0/E-Fenton对DMP的降解过程中,相对稳定的溶液pH值和充足的Fe2＋量有利于E-Fenton试剂对DMP的降解反应。同时考察了Fe0/E-Fenton反应的初始pH值和纳米Fe0投加量对DMP降解的影响。研究结果表明,当DMP的初始浓度为50 mg.L-1时,溶液的最佳pH值和Fe0的投加量分别为3.0、60 mg.L-1,且DMP溶液在90 min内可以达到完全降解,降解速率符合准一级动力学方程：ln（C0/C）=0.056t-0.072,R=0.996,降解速率常数为0.056 min-1。     

静息细胞转化制备6-脱氧-6-氨基（ⅣI羟乙基）--α-L-呋喃山梨糖的研究

以N-羟乙基葡萄糖胺为底物,采用氧化葡萄糖酸杆菌静息细胞转化制备6-脱氧-6-氨基（N-羟乙基）-α-呋喃山梨糖,考察了生物转化条件（温度、pH值、摇床转速、细胞浓度、底物浓度、金属离子、转化时间等）对转化反应的影响,并通过单因素实验和正交实验,确定摇瓶转化的最优条件如下：反应温度为25℃,pH值为6．0,摇床转速为200r·min^-1,细胞浓度为60g·L^-1,底物浓度为60g·L^-1,转化时间为48h,在此条件下目标产物的产率为87．5％。研究还发现在转化液中添加Mg^2＋对转化具有促进作用。     

Ca4（1＋x）／5Mg（1＋x）／5Zr4Si2xP（6—2x）O24磷酸盐陶瓷材料的制备及力学性能

以化学纯CaCO3、4MgCO3·Mg（OH）2·5H2O、ZrO2、SiO2和（NH4）H2PO。微粉为原料,采用高温固相反应法合成了Ca4（1＋x）／5Mg（1＋x）／5Zr4Si2xP（6-2x）O24（CMZP）粉体,其中x=0、0．1、0．2、0．3。XRD测试结果表明在400℃下保温2h、1150℃下保温4h,能够合成单相的CMZP粉体,粉体千压成形后经冷等静压处理,在1350℃保温8h能烧结得到相对密度为97．5％的陶瓷试样,其平均抗弯强度为50MPa。     

荧光假单孢菌高活性木聚糖酶产酶研究

从盐碱土中获得一样荧光假单孢菌（P.flu．01）,研究了该菌木聚糖酶产酶条件。虽然木聚糖为木聚糖酶产酶最佳碳源,但以未处理的玉米芯为碳源,胰蛋白际和酵母混音为氮源时．经60h培养后,木聚糖酶活高达164．OIU／mL,而CMC酶活很低,只有0．29IU/mL。同时该菌对pH值具有广泛的适应性,在起始pH＝6．0－11．0范围内其木聚糖产酶能力相差不大。有机氛胰蛋白股和酵母混音比无机氛更有利于酶活的提高,并且木聚糖酶活力的提高和有机氟含量增加成正比。玉米芯的物理状态即粗细度对产酶影响不大,但玉米芯的含量增加对广酶有强烈的挺进作用。该酶最合适pH值为6．5,最适反应温度为50℃。     

（-）-α-蒎烯选择性氧化合成（＋）-2-羟基-3-蒎酮的研究

以（-）-α-蒎烯为原料,经过选择性氧化合成（＋）-2-羟基-3-蒎酮。研究了其合成工艺条件,对不同氧化体系、氧化剂用量、反应时间以及反应温度等因素进行了探讨。结果表明,（-）-α-蒎烯选择性氧化合成（＋）-2-羟基-3-蒎酮合适的工艺条件为：13．7g（纯度为93．0％）的（-）-α-蒎烯,在α-蒎烯与高锰酸钾物质的量之比为1：2,溶剂丙酮与水的用量是110：12（mL：mL）,反应温度为0-5℃,反应时间为5h,α-蒎烯转化率为97．1％,（＋）-2-羟基-3-蒎酮选择性为78．4％,纯度为92．1％,得率为76．1％,比旋光度为[α]D28＋26°（c=0．5mol／L,CHCl3）。另外,采用IR、GC-MS和1H NMR和13C NMR等对（＋）-2-羟基-3-蒎酮结构进行了表征。     

5-（3-甲基-2-呲啶）-亚甲基若丹宁合成与钯的改进FIA光度法

合成了试剂5-（3-甲基-2-呲啶）-亚甲基若丹宁（MPMR）,研究了其与钯的显色反应最佳条件。利用自制的流动比色装置,尝试了一种新的流动注射光度检测技术,一次注样便产生两峰一谷响应曲线,使分析灵敏度大幅度提高。在pH值为3．5～6．5介质中MPMR和Pd^2＋生成摩尔比为2：1配合物,λmax=436nm,ε=8．79×10^4L／（mol·cm）,进样频率120次／h,钯含量在0～1．4,μg／mL范围内符合比耳定律。该方法用于钯溶化剂中钯的测定,结果满意。     

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.