11种杀菌剂对水稻纹枯病菌的毒力比较

采用菌丝生长速率法测定了11种杀菌剂对水稻纹枯病菌的抑菌活性。结果表明，水稻纹枯病菌对三唑类杀菌剂己唑醇、苯醚甲环唑、腈菌唑、戊唑醇、烯唑醇、三唑醇的敏感性依次下降，EC50值均在0．5μg／mL以下，EC90值均低于10μg／mL；水稻纹枯病菌对1227和C8—10两种季铵盐阳离子表面活性剂的敏感性高于井冈霉素，但低于三唑类杀菌剂，EC50分别为15．0394μg／mL和4．0735μg／mL；水稻纹枯病菌对苯并咪唑类杀菌剂甲基硫菌灵和多菌灵毒力差异较大，甲基硫菌灵抑菌活性低于井冈霉素，EC50为10．2330μg,／mL，多菌灵的抑菌活性远高于井冈霉素，其毒力与三唑类药剂相当，其EC50为0．2656μg／mL。     

几种杀菌剂及其混配剂对香蕉枯萎病菌的毒力测定

采用菌丝生长速率法测定了8种杀菌剂对香蕉枯萎病菌的毒力,并在此基础上用Horsfall的毒力试验设计和共毒系数法进行了混配剂的筛选. 结果表明:450 g/L咪鲜胺EW的EC50值最小,为0.038 4 mg/L,毒力最强;450 g/L戊唑醇SC、25%吡唑醚菌酯EC、30%丙环唑·苯醚甲环唑EC、50%多菌灵WP、25%丙环唑EC、10%苯醚甲环唑WG、15%霉灵AS的毒力依次减弱,EC50 值分别为:0.245 8、0.385 7、0.943 5、1.379 8、2.438 4、10.981 4、33.333 0 mg/L. 多菌灵与霉灵按EC50值剂量9∶1比例混配后共毒系数为131.63,具有一定的增效作用,多菌灵与丙环唑按EC50值剂量3∶7的比例混配后共毒系数为691.87,具有显著的增效作用. 咪鲜胺与霉灵、咪鲜胺与丙环唑、咪鲜胺与多菌灵3组混配药剂均无显著增效作用.     

创制杀菌剂啶菌恶唑的生物活性及应用研究(Ⅲ)--番茄叶霉病

啶菌恶唑(SYP—Z048)对番茄叶霉病有较高的杀菌活性，离体活性EC50值为0.29μg／ml，盆栽试验结果EC90为90．66μg／ml；田间小区试验结果表明：25％啶菌恶唑乳油使用剂量为200～400ga．i．／hm^2，施药2～3次，能有效控制番茄叶霉病的发生与危害，防效与腈菌唑相当，优于多菌灵、甲基硫菌灵及代森锰锌。     

烯唑醇对水稻重要病原菌的毒力测定及复配研究

烯唑醇对稻纹枯病菌、稻瘟病菌和稻曲病菌具有很强的抑制效果,EC50分别为0.033、0.085和0.147μg/ml。烯唑醇与多菌灵以0.5:10、1.0:10、1.5:10、2.0:10和2.5:10五种比例复配,除1.5:10复配剂对稻瘟病菌的抑制有一定的增效作用外,其他复配剂对稻瘟病菌和纹枯病菌的抑制大都表现为相加作用,而对稻曲病菌的抑制则多为拮抗作用。因此,就增效而言,两者复配对上述三种水稻病害的防治意义不大。     

蛇床子和苦参活性成分的联合毒力测定及混剂的抑菌活性

采用室内平皿菌丝生长速率法研究了蛇床子和苦参有效活性成分对烟草赤星病菌的毒力及联合毒力。结果表明蛇床子和苦参有效活性成分对烟草赤星病菌都有一定的抑制作用,EC50分别为80.0、27.9μg／ml,将两者按照一定比例复配后,EC50为33．3μg／ml,增效比值为2．80,具有明显的增效作用。同时研究了蛇苦混剂对病原菌的抗生作用、菌丝形态以及孢子萌发的影响。     

防治番茄青枯病复配剂筛选

采用“农药-菌悬液混合”杀菌法．测定了农用链霉素等4种单剂对番茄青枯病菌(Burkhokderia solanacearum)的室内毒力测定，求出各单剂的EC50，并根据“按比例混合法”^[4]复配，结果表明：复配剂I、Ⅱ、Ⅲ都有增效作用，其中以复配剂I的增效作用最明显，最高杀菌率达97．4％(农用链霉素与水合霉素以1：4混配所得制剂)；其次是复配剂Ⅱ，最高杀菌率为91．5％(农用链霉素与立枯净以4：1混配所得制剂)；复配剂Ⅲ的增效作用最低，最高杀菌率为79．3％。     

苦参提取液及其与多菌灵混配对黄瓜灰霉病菌的毒力测定

室内采用生长速率法测定了苦参水提取液和酸碱提取液及其与多菌灵不同混配组合对黄瓜灰霉病菌的毒力。结果表明,苦参水提取液对黄瓜灰霉病菌菌丝生长的抑制效果优于苦参酸碱提取液,EC50分别为110.00μg/mL和280.60μg/mL。多菌灵与苦参水提取液混剂配比为10﹕1时,对黄瓜灰霉病菌菌丝生长的抑制具有明显的增效作用,EC50为0.03μg/mL,共毒系数为278.3。     

嘧菌酯对稻瘟病菌的生物活性

嘧菌酯对稻瘟菌菌丝生长、孢子萌发、产孢量、孢子致病力和黑色素合成具有强烈的抑制作用。嘧菌酯离体活性受培养基组分影响，可酵解碳源具有拮抗作用。SHAM对嘧菌酯抑制孢子萌发的活性具有增效作用。嘧菌酯对稻瘟菌63个菌株的EC50为0．0010-0．0906μg／ml，平均EC50为0．02231μg／ml。盆钵试验表明，秧苗对嘧菌酯的商品制剂25％嘧菌酯具有良好的内吸性；兼有保护作用和治疗作用。25％嘧菌酯对稻瘟菌有一定的田间防效，且对水稻增产作用明显。     

丙硫菌唑与5种常用杀菌剂复配对水稻、小麦纹枯病菌的联合毒力

为明确丙硫菌唑与5种常用药剂的复配潜力,笔者采用菌落生长抑制法,测定丙硫菌唑与各杀菌剂不同配比对水稻、小麦纹枯病菌的联合毒力。结果表明,丙硫菌唑单剂对水稻、小麦纹枯病菌的EC_(50)值分别为2.202 5μg/mL和3.416 2μg/m L,其他几种杀菌剂单剂的EC_(50)值则在0.034 7～1.792 2μg/mL和0.067 0～1.446 3μg/mL。将丙硫菌唑与各药剂分别按3∶1、2∶1、1∶1、1∶2和1∶3的比例复配后,对于小麦纹枯病菌来说,以丙硫菌唑与氟环唑复配增效最为明显,2∶1配比下最大SR值可达6.69;对于水稻纹枯病菌,则以丙硫菌唑与吡唑醚菌酯3∶1复配联合毒力最强,SR值为1.92;丙硫菌唑与咯菌腈复配效果最差,各配比下对水稻、小麦纹枯病菌的SR值均小于1.0,说明除咯菌腈外,丙硫菌唑具有与多种杀菌剂复配,并进一步研发成制剂的潜力。     

乙环唑对柑橘青霉菌Penicillium italicum毒力的生物测定

就乙环唑对柑桔青霉病病菌的抑制毒力与万利得、扑霉灵、甲基托布津及多菌灵进行了比较测定.结果显示,9%乙环唑EC对柑橘青霉菌孢子萌发的最小抑制浓度为2.6μg/L,明显低于70%甲基托布津WP(70μg/L)和50%多菌灵WP(34μg/L),但高于50%万利得EC(0.8μg/L)和45%扑霉灵EC(1.4μg/L).9%乙环唑EC与50%万利得EC、45%扑霉灵EC混用均能够提高对柑橘青霉菌孢子萌发的抑制效力.9%乙环唑的抑菌毒力EC50=0.56μg/L,EC90=1.93μg/L,抑制效力比90%万利得EC低1.8倍左右.     

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.     

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.     

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.