一次性除草剂新禾葆(杀·苄)的研究

和除草剂单剂的理论等效线相比,杀草丹和苄嘧磺隆混用的增效值高达４．３倍,增效作用显著。新禾葆热贮处理的稳定性良好,其有效成分杀草丹的分解率为０,苄嘧磺隆的分解率为７．７％。新禾葆防除稗草［Ｅｃｈｉｎｏｃｈｏｌａｇｒａｓ－ｇａｌｉ（Ｌ．）Ｂｅａｕｖ］和千金子［Ｌｅｐｔｏｃｈｌｏａｃｈｉｎｅｎｓｉｓ（Ｌ．）Ｎｅｓｓ］特效,且对水稻安全。     

菊酯、有机磷类混合制剂开发研究初报

作者以合剂共毒系数为增效参考指标,以田间实证增效效果为重要依据,选用棉铃虫、菜蚜类和麦蚜类等五种重要农业害虫为供试虫,经过1983—1988年的6年筛选和增效研究,发现由拟除虫菊酯类同有机磷类农药复配的二元混合制剂,大多数有较显著的增效作用,共毒系数超过130者,占试验总数的84.4％,其中超过200者占增效数的48.2％。以有机磷类农药复配组合中,共毒系数超过130者占总数的58.3％,但无超过200者。不同害虫的田间增效试验亦得到合剂比单剂防效高的增效结果。     

戊唑醇和枯草芽孢杆菌协同作用防治蚕豆枯萎病及增效机理初探

试验结果表明:戊唑醇(tebuconazole)和枯草芽孢杆菌Bacillus subtilis生防菌株B-916协同作用,对抑制蚕豆枯萎病病原菌Fusarium spp.菌丝生长和防治蚕豆枯萎病均有显著的增效作用。通过B-916利福平抗药性标记回收法测定了戊唑醇和B-916复配后B-916在土壤中的定殖状况,结果表明:戊唑醇对B-916在土壤中定殖有促进作用,能减缓B-916群体数量大幅度下降,帮助B-916发挥生物防治作用。这可能是戊唑醇和枯草芽孢杆菌B-916协同作用的增效机理之一。     

Cross-Resistance to Imidacloprid in Strains of German Cockroach (Blattella germanica) and House Fly (Musca domestica)

The toxicity of a promising new insecticide, imidacloprid, was evaluated against several susceptible and resistant strains of German cockroach and house fly. Imidacloprid rapidly immobilized German cockroaches followed by a period of about 72 h during which some cockroaches recovered. After 72 h there was no further recovery. Imidacloprid-treated houseflies were immobilized more slowly than treated cockroaches, with the maximum effect observed after 72 h, and there was no recovery. Based upon 72-h LD₅₀ values imidacloprid was moderately toxic to German cockroaches (LD₅₀ values were 6–8 ng mg^-1) and had only low toxicity to house flies (LD₅₀ 140 ng mg^-1). Piperonyl butoxide (PBO) blocked the observed recovery in German cockroaches. PBO also greatly enhanced the 72-h LD₅₀ of imidacloprid from 43- to 59-fold in cockroaches and 86-fold in house flies. Two strains of German cockroach (Baygon-R and Pyr-R) showed >4-fold cross-resistance to imidacloprid. This cross-resistance could not be suppressed by PBO, suggesting that P450 monooxygenase-mediated detoxication is not responsible for this cross-resistance. Variation in the level of synergism observed with PBO (between strains) suggests the ‘basal’ level of monooxygenase-mediated detoxication of imidacloprid is quite variable between strains of German cockroach. The AVER and LPR strains of house fly showed significant cross-resistance to imidacloprid. PBO reduced the level of cross-resistance in AVER from >4·2-fold to 0·5-fold (i.e. the AVER strain LD₅₀ was half that of the susceptible strain when both were treated with PBO), but PBO did not suppress the cross-resistance in LPR. These data suggest monooxygenases are the mechanism responsible for cross-resistance to imidacloprid in AVER, but not in the LPR strain. © of SCI.     

Effects of Ge-132 and Selenium on Antioxidative Function of Cow

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Evidence for synergism of the antimicrobial peptide piscidin 2 with antiparasitic and antioomycete drugs

Piscidins are potent, broad‐spectrum, host‐produced antimicrobial peptides (AMPs) that appear to constitute the most common AMP family in teleost fish. Here, we show that piscidin 2 has potent activity against the water mould Saprolegnia, one of the most important pathogens of freshwater fish. The minimum oomyceticidal concentration (MOC₁₀₀) of piscidin 2 against zoospores of three pathogenic isolates of Saprolegnia ranged from 12.5 to 25.0 μg mL^?1. This piscidin concentration is well within levels that have been estimated to be present in at least some fish (1–32.5 μg mL^?1). In the presence of either copper or malachite green, two drugs commonly used to treat water moulds, there was evidence for partial synergism (PSYN) with piscidin 2. There was also evidence for PSYN after exposure of the ciliate parasite Tetrahymena pyriformis to piscidin 2 plus copper. Our data provide further evidence that piscidins may be an important host defence against skin and gill pathogens and that the piscidin levels in host tissue might influence the success of drug treatments.     

植物挥发物对黏虫性诱剂引诱效果的影响

黏虫Mythimna separata(Walker)是一种重要的季节性、远距离迁飞害虫,近些年在我国的发生有明显加重的趋势。本试验运用电生理学技术和风洞技术,测定黏虫的触角对5种植物挥发物的反应,并进一步评价了植物挥发物与黏虫性诱剂在田间联合应用对成虫的诱捕效果,为黏虫性诱剂的高效利用和虫情监测提供依据。电生理学试验结果表明,黏虫雌、雄蛾对苯乙醛、芳樟醇、Z-3-己烯基乙酸酯的反应有显著差异(P0.05)。除α-法尼烯外,黏虫雌、雄蛾对植物气味化合物的触角电位值均随浓度的升高而升高;风洞行为试验结果表明,与对照相比,雄蛾对苯乙醛、Z-3-己烯基乙酸酯、β-石竹烯均表现出逆风飞行行为(比例分别为50.6%、50.3%和44.9%),芳樟醇则对雄蛾具有一定的驱避作用。田间试验结果表明,单一植物挥发物对黏虫的吸引力较小,且各挥发物之间无显著差异;苯乙醛、β-石竹烯、Z-3-己烯基乙酸酯和性诱剂组合配方的引诱效果最佳,诱捕量是单独使用性诱剂的1.8倍(P0.05)。     

Toxicity of spinosad to susceptible and resistant strains of house flies,Musca domestica

The toxicity of spinosad, a new insecticide derived from the bacterium Saccharopolyspora spinosa, was evaluated against susceptible and resistant strains of house fly (Musca domestica L.). Spinosad was highly toxic to house flies based on 72-h LD₅₀ values and the symptoms of poisoning were consistent with a neurotoxic mechanism of action. Spinosad was relatively slow acting, with the maximum toxicity noted at 72 h. Piperonyl butoxide and S,S,S,-tribu-tylphosphorotrithioate synergized the toxicity of spinosad by 3·0- and 1·8-fold, respectively, while diethyl maleate had no significant effect. These results suggest that there is a small degree of monooxygenase-mediated spinosad detoxification in house flies, while hydrolases may be only minimally important and glutathione transferases may have no role. There were no substantial levels of cross-resistance detected, except in the LPR strain where a low 4·3-fold cross-resistance was observed. The cyclodiene-resistant OCR strain was 2·7-fold more sensitive to spinosad than the susceptible strain (CS). These results suggest that cross-resistance may not be a limiting factor for the use of spinosad against house flies. © 1998 Society of Chemical Industry     

Efficacy and Mechanism of Action of Marine Alkaloid 3,10-Dibromofascaplysin in Drug-Resistant Prostate Cancer Cells

Efficacy and mechanism of action of marine alkaloid 3,10-dibromofascaplysin (DBF) were investigated in human prostate cancer (PCa) cells harboring different levels of drug resistance. Anticancer activity was observed across all cell lines examined without signs of cross-resistance to androgen receptor targeting agents (ARTA) or taxane based chemotherapy. Kinome analysis followed by functional investigation identified JNK1/2 to be one of the molecular targets of DBF in 22Rv1 cells. In contrast, no activation of p38 and ERK1/2 MAPKs was observed. Inhibition of the drug-induced JNK1/2 activation or of the basal p38 activity resulted in increased cytotoxicity of DBF, whereas an active ERK1/2 was identified to be important for anticancer activity of the alkaloid. Synergistic effects of DBF were observed in combination with PARP-inhibitor olaparib most likely due to the induction of ROS production by the marine alkaloid. In addition, DBF intensified effects of platinum-based drugs cisplatin and carboplatin, and taxane derivatives docetaxel and cabazitaxel. Finally, DBF inhibited AR-signaling and resensitized AR-V7-positive 22Rv1 prostate cancer cells to enzalutamide, presumably due to AR-V7 down-regulation. These findings propose DBF to be a promising novel drug candidate for the treatment of human PCa regardless of resistance to standard therapy.     

化学杀虫剂对绿僵菌的影响及菌药混用研究

研究 6种化学杀虫剂对金龟子绿僵菌分生孢子萌发的影响 ,结果表明 6种化学杀虫剂皆对绿僵菌分生孢子有程度不同的抑制作用 ,浓度愈高 ,抑制作用愈强 ,但氧化乐果对绿僵菌孢子萌发抑制作用最小 .对马尾松毛虫的生物测定结果表明 :绿僵菌 (含孢量为 1 .9× 1 0 10个· L-1)与敌杀死 ( 1∶ 60 0 0 0 ) ,辛硫磷 ( 1∶ 1 0 0 0 0 ) ,灭杀毙 ( 1∶ 2 5 0 0 0 )和灭幼脲 ( 1∶ 1 5 0 0 0 )混用有明显的增效作用 ,其 LT50 值比单用绿僵菌 (含孢量为 1 .9× 1 0 10个· L-1)分别提前了 7、6、5和 3d