枯草芽孢杆菌对黑土中可培养微生物的生态效应

研究了微生物农药枯草芽孢杆菌对东北黑土中可培养微生物的生态影响.其动态变化表明:低质量分数枯草芽孢杆菌对细菌总数没有明显影响,较高质量分数枯草芽孢杆菌町促进细菌总数的显著增加,其中质量分数在3200 mg/kg时,枯草芽孢杆菌对细菌的刺激强度最高,为对照的11倍.枯草芽孢杆菌对土壤中的放线菌也有刺激作用,刺激强度最高时,放线菌数量可增至对照的8.3倍左右.枯草芽孢杆菌对真菌的敏感性较低,只有质量分数高达3200 mg/kg时,才对真菌产生明显刺激作用,最高刺激强度为同时期对照的29倍.     

辛硫磷对土壤微生物种群结构的影响

采用室内培养法研究了土壤中200～1000mg／kg三种不同质量分数的辛硫磷对好氧性细菌、真菌和放线菌三大主要微生物种群数量及其优势菌生长速率的影响。结果表明，土壤中各微生物种群对不同质量分数的辛硫磷具有各自不同的反应。辛硫磷对细菌种群数量及优势细菌生长速率的影响表现为明显的刺激效应，且随加药质量分数的提高刺激效应越明显，而且对种群数量的刺激效应随加药时间延长趋势越明显；对放线菌种群数量的影响表现为抑制效应，且随药剂质量分数的提高抑制效应越明显。但随着加药时间的延长，这种抑制效应又趋于减弱．逐渐恢复到正常水平。但对优势放线菌生长速率的影响却表现为刺激效应；对真菌种群数量及优势真菌生长速率的影响也表现为抑制效应，且随药剂质量分数的提高和加药时间的延长抑制效应越明显。因此，有望从土壤中筛选到能降解辛硫磷的细菌，同时真菌可以作为土壤受辛硫磷污染的敏感指示菌。     

高浓度CO_2入侵包气带对土壤微生物的影响

以鄂尔多斯CO2地质储存地的土壤和典型植被小麦和黑麦草为研究对象,通过原位模拟实验,考察了不同浓度CO2入侵包气带对土壤细菌、真菌、放线菌数量及细菌群落多样性的影响。结果表明,高浓度CO2入侵包气带,对土壤微生物生长有一定的抑制作用,植被可以提高CO2入侵条件下土壤微生物的抗逆性,但不同植被对土壤微生物抗逆性的调节具有一定差异;高浓度CO2入侵包气带,使Pedobacter(地杆菌属)、Akkermansia(疣微菌门)等细菌的丰度提高,unclassified_Betaproteobacteria(β-变形菌属)等细菌的丰度降低,细菌Thauera aminoaromatica(陶厄氏菌属)和Nitrospira(硝化螺菌属)完全消亡,并产生了Flavobacterium denitrificans(黄杆菌属)、Haematobacte(红杆菌属)、Ferrithrix(热袍菌门)新菌种。高浓度CO2入侵包气带对土壤微生物群落结构影响显著,但土壤微生物主要建群种未变。     

攀枝花尾矿土壤微生物数量及土壤酶活性分析

以攀枝花东区马家田尾矿坝区域土壤及攀枝花公园土壤为研究对象,分析其理化性状、土壤微生物数量与土壤酶活性及其相关性。结果表明,尾矿坝土壤pH与含水量较攀枝花公园土壤更低;尾矿坝土壤中各类菌群数量为细菌放线菌真菌;土壤酶活性大小为转化酶过氧化氢酶纤维素酶脲酶,分别为12.99 mg/g·24 h、0.85 mL/g·10 min、0.32 mg/g·24 h、0.013 mg/g·24 h;土壤细菌、真菌、放线菌数量随着土壤含水量的增长而降低;细菌数量随着脲酶的增长而降低;放线菌数量随着转化酶增长而增长。     

腐殖酸对烤烟土壤性状及烟叶品质的影响

2006-2007年在河南郏县进行田间试验，研究腐殖酸对土壤微生物数量、酶活性和烟叶品质的影响。试验结果表明，使用腐殖酸肥料后，耕层土壤细菌、真菌、放线菌、磷细菌、钾细菌和氨化细菌的数量，土壤蔗糖酶、脲酶、     

几种杀线剂对土壤微生物数量及真菌多样性影响

研究了土壤中放线菌、细菌和真菌数量及多样性对阿维菌素、涕灭威、克线丹等3种杀线剂的响应.结果表明:土壤微生物对10%克线丹GR、5%涕灭威GR和1.8%阿维菌素EC三种杀线剂的反应不同,对放线菌数量的影响不明显,试验期间各处理土壤中放线菌的数量均表现为先升高后降低.42 d时各处理土壤中放线菌数量达峰值,此时阿维菌素处理的土壤中放线菌数量显著高于对照和其他2个处理(P<0.05);3种杀线刹对土壤中真菌和细菌的影响不同,阿维菌素和克线丹分别在施药后21 d和42 d左右对土壤中真菌有刺激作用.而后刺激作用消失,涕灭威显著抑制土壤中真菌的增殖(Jp<0.05),但刺激土壤中细菌的增加;克线丹在施药21 d前对细菌增殖有刺激作用而后表现抑制.且对土壤真菌的多样性影响较小.     

腐植酸用量对土壤微生物数量和烟叶香气品质的影响

正为探明腐植酸用量对土壤微生物数量和烟叶香气品质的影响,通过试验研究了腐植酸用量(0、60、120和180 kg/hm~2)对土壤微生物数量和烟叶净光合速率、香味物质含量、感官品质及经济性状的影响。试验结果表明:随着腐植酸用量的增加,土壤放线菌数量显著提高、细菌和真菌数量     

土壤微生物种群与酶活性对草铵膦和草甘膦胁迫响应的差异

[目的]通过研究草铵膦和草甘膦对土壤微生物种群及酶活性的影响,为评价2种除草剂对土壤生态环境效应的差异提供参考。[方法]采用室内培养法研究土壤细菌、真菌、放线菌种群数量及土壤脲酶、酸性磷酸酶和酸性转化酶活性对50～500 mg/kg 5种不同质量分数草铵膦和草甘膦的胁迫响应。[结果]草铵膦和草甘膦对土壤细菌和放线菌种群的生长表现为低剂量促进高浓度抑制;对土壤真菌种群的生长表现为抑制作用;对土壤脲酶和酸性磷酸酶活性也表现为抑制作用,且随药剂剂量提高逐渐增强;对土壤酸性转化酶活性草铵膦表现为低剂量促进高剂量抑制,草甘膦表现为随药剂剂量提高促进作用逐渐增强。[结论]土壤可培养细菌、真菌、放线菌,脲酶、酸性磷酸酶、酸性转化酶对2种除草剂胁迫的响应均表现为草铵膦敏感于草甘膦。     

不同施肥组合对科尔沁沙地南缘沙地土壤健康指标的影响

为研究不同施肥组合对沙地土壤改良的效果,以辽宁省阜新市彰武县的沙地土壤为考察对象,开展了试验研究。试验以不施肥为对照(CK)处理,设置生物有机肥分别与含腐殖酸肥料(OH)、含聚谷氨酸肥料(OP)和中微量元素肥(OM)混施3个施肥处理,测定施肥后6、12、18个月的土壤中微生物数量和土壤理化性状的变化。结果表明：不同施肥处理的土壤中微生物数量均呈现细菌>放线菌>真菌的变化趋势,其中OH处理的细菌数量最多,3个取样时间的细菌数量平均值为1.510×10⁷ cfu/g,是CK处理的5.2倍;施肥处理的土壤中全磷、全钾和有机质含量均得到提高,OP处理的全钾含量平均值最高,质量分数为5.96 g/kg;施肥处理的土壤pH均呈下降趋势;施肥处理的地上部植物生物量提高。施用不同组合的肥料可以有效提高土壤微生物的数量,改善土壤理化性状,提高地上部植物生物量,是一种合理的沙地改良措施。     

草甘膦对土壤微生物影响的研究

研究了草甘膦在5种浓度下对土壤微生物种群数量及土壤中细菌、放线菌、真菌生长速率的影响。结果表明,在供试浓度下,该除草剂对土壤微生物的种群数量及土壤中细菌、放线菌和真菌生长速率均具有一定的抑制作用。并随药剂浓度的升高抑制作用逐渐增强。加药后2～7d,对细菌种群数量的抑制率为17．5％～100％,抑菌圈直径达0.07～0．87cm;对放线菌种群数量的抑制率为2．1％～100％,抑菌圈直径达0～0．83cm;对真菌种群数量的抑制率为9.9％～100％,生长速率的抑制率达7．3％～85．7％。随着加药时间的延长,对土壤微生物的抑制作用又逐渐减弱。     

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.     

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.     

Novel polyurethane coating technology through glycidyl carbamate chemistry

Glycidyl carbamate chemistry combines the excellent properties of polyurethanes with the crosslinking chemistry of epoxy resins. Glycidyl carbamate functional oligomers were synthesized by the reaction of polyfunctional isocyanate oligomers and glycidol. The oligomers were formulated into coatings with several amine functional crosslinkers at varying stoichiometric ratios and cured at different temperatures. Properties such as solvent resistance, hardness, and impact resistance were dependent on the composition and cure conditions. Most coatings had an excellent combination of properties. Studies were carried out to determine the kinetics of the curing reaction of the glycidyl carbamate functional oligomers with multifunctional and model amines. Detailed kinetic analysis of the curing reactions was also undertaken. The results indicated that the glycidyl carbamate functional group is more reactive than a glycidyl ether group. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, on October 27–29, 2004, in Chicago, IL.