蔬菜农药残留速测结果异常的原因及对策

介绍了蔬菜中有机磷和氨基甲酸酯类农药残留快速检测技术的原理,分析了检测中出现结果异常的各种原因,并提出了减少检测结果误差,提高检测结果准确性的对策。     

正确选用农药 提高防虫效果——九江地区防治棉虫“八看用药”经验

药剂治虫,在当前防虫工作中还是一种重要手段,而对药剂的选择,则是决定防治成败和效果好坏的关键。解放以来我区防治棉虫使用杀虫剂约51种左右,其中有机氯制剂6种,有机磷制剂21种,有机氯有机磷混合剂7种,氨基甲酸酯类药剂7种,无机药剂3种,植物性药剂3种,混合农药2种,生物农药1种,烟雾剂1种。各地应用上述药剂取得了一些经验,象混合用药,轮换用药,加辅助剂和发展低毒低残留品种,都收到了很好的效果。为了进一步发挥农药的效益,搞好棉花治虫,现把各地防虫所见,集成“八看用药”。一、看害虫种类选用农药     

几种淡水鱼肌肉乙酰胆碱酯酶的盐析提取及农药敏感性研究

以鲢鱼、镛鱼和罗非鱼肌肉组织为材料,研究乙酰胆碱酯酶AChE的盐析提取方法及农药敏感性。结果表明,3种淡水鱼肌肉组织在55%硫酸铵饱和度时得到的沉淀酶总活力最高,乙酰胆碱酯酶的比活力分别达到0.264,0.263,0.221 U/mg, 纯化倍数分别为1.222,1.277,1.190,回收率分别为27.626%,37.621%,26.441%。5种有机磷农药(敌敌畏,辛硫磷,马拉硫磷,乙酰甲胺磷,氧化乐果)对3种淡水鱼肌肉乙酰胆碱酯酶有抑制作用,其中罗非鱼AChE对敌敌畏最敏感,抑制中浓度I50为0.14 μg/mL,对马拉硫磷最不敏感,抑制中浓度I50为11.202 μg/mL     

基质固相分散—气相色谱法测定油菜籽中多种有机磷农药残留

采用基质固相分散法从油菜籽中提取、净化油菜生产中常用的5种有机磷农药，用配有火焰光度检测器的气相色谱定性和定量分析。通过对基质固相分散吸附剂、洗脱剂、净化材料与方式的优化，建立了油菜籽中5种常用有机磷农药残留分析的前处理方法。利用所建立的方法进行3个水平（0.1 mg/kg，0.25 mg/kg，0.5 mg/kg）加标回收实验，结果表明，平均回收率80.3.%-104.4%，相对标准偏差＜10%，方法的回收率和相对标准差满足农药残留检测中准确度和精密度的要求。在此基础上对收集到的150份油菜籽样品进行5种有机磷农药残留检测，检出率为2%。     

3类5种农药对马铃薯块茎蛾幼虫防治效果的对比试验

3大类农药(有机磷、氨基甲酸酯、拟除虫菊酯)中5种代表性农药对马铃薯块茎蛾进行毒力比较,结果显示:马铃薯块茎蛾对氨基甲酸酯类的万灵较敏感,毒力最大,平均LC50=46.986,对敌敌畏等有机磷类农药最不敏感,抗性很高;对拟除虫菊酯类的敌杀死敏感性居中LC50=159.102。     

液相色谱法对茶叶中农药残留量的检测方法研究

茶叶逐渐成为人们日常的绿色健康饮品,其卫生、安全都与人们的身体健康有直接的联系。本文综述了茶叶中农药残留的具体分类的研究结果,重点分析了液相色谱法在茶叶中有机氯类、有机磷类、氨基甲酸酯类以及拟除虫菊酯类等农药的检测研究,通过分析检测条件(色谱、分析)的优化方法提出"指纹识别"图谱的建立,这对茶叶中农药残留量的检测方法的改进具有一定的指导意义。     

麦麸酯酶的分离纯化及酶学性质研究

为了能更好地将麦麸酯酶用于检测食品中的农药残留,采用硫酸铵分段沉淀、透析、SephadexG-200凝胶层析、超滤浓缩等方法对麦麸中提取的酯酶粗液进行了分离和纯化,并对其酶学性质进行了研究。结果表明,得到的麦麸酯酶比活力为289.14U·mg~(-1),回收率为47.7%,纯化倍数为16.17。麦麸酯酶的分子量约为26.0kDa,最大紫外吸收峰为224nm和280nm,最适反应温度为30℃,稳定范围为25~40℃;最适pH为8.0,pH稳定范围为4.0~8.0。Cu~(2+)、Mg~(2+)、Ca~(2+)、Al~(3+)、柠檬酸钠、四硼酸钠均对麦麸酯酶有抑制作用,而Fe~(2+)、Mn~(2+)、柠檬酸、硫酸铝钾对该酶有促进作用;以α-乙酸萘酯为底物的动力学参数K_m和V_(max)值分别为0.85mg·mL~(-1)和0.93mg·mL~(-1)·min~(-1)。4℃时,麦麸酯酶半衰期为10.4d,而25℃时,酯酶半衰期为8.6d。本研究结果对麦麸酯酶的应用具有一定参考价值。     

等效面法分析3种氨基甲酸酯类农药对乙酰胆碱酯酶的联合作用

为了更好地评估与预测三元混合物的毒性相互作用,以3种氨基甲酸酯类农药残杀威、灭多威、速灭威为研究对象,应用均分等效面设计(EESD)法配制三元混合物,应用直接均分射线设计法(EquRay)配制两两混合的二元混合物,测定混合物对乙酰胆碱酯酶(AChE)的抑制效应,基于三角形的3次插值方法构建三元混合物在20%、50%、80%效应的等效面,以浓度加和(CA)与独立作用(IA)为参考模型分析混合物的毒性相互作用。结果表明,Weibull函数能良好地拟合3种氨基甲酸酯类农药及其混合物对AChE的浓度-效应数据(R2>0.99,RMSE<0.03)。基于等效面分析,残杀威、灭多威、速灭威的三元及二元混合物毒性符合CA模型,呈现加和作用,而IA轻微高估了混合物的毒性。共毒系数法也证实这3种氨基甲酸酯类农药呈现加和作用。回归分析发现三元混合物毒性(pECx)与速灭威的浓度分数具有良好的负相关关系。均分等效面设计法与等效面分析法可用于有效评估三元混合物的联合毒性。      

有机磷农药残留物在茶叶上的分析研究

有机磷农药在茶叶病虫害的防治中扮演着十分重要的角色,但是,有机磷农药会在茶叶、各类环境基质、动植物体,甚至是人类身体中残留富集,给人类的生存环境带来巨大的威胁。本文以有机磷农药残留物降解为切入点,主要分析有机磷农药在茶叶产品的残留现状,深入探讨现阶段有利于有机磷农药残留的快速预处理和检测的技术,针对食品中农药残留物的降解方法,归纳了茶叶中有机磷类农药的分析和降解,这对茶叶产业经济的发展,保障人们的环境和食品安全,具有一定的理论指导意义。     

自动顶空气相色谱法测定人参中二硫代氨基甲酸酯的残留量

目的建立一种测定人参中二硫代氨基甲酸酯类农药残留的自动-顶空气相色谱方法。方法把人参样品放入自动顶空进样瓶中,放入密闭的加热容器中,在氯化亚锡-硫酸溶液环境中,二硫代氨基甲酸酯类农药被酸解生成二硫化碳,采用自动-顶空气相色谱法(检测器:ECD)测定,以二硫化碳计二硫代氨基甲酸酯总残留量,外标法定量。结果二硫化碳浓度在0.05~2.0μg/mL时,呈良好的线性关系(r=0.997);检出限为0.030mg/kg;精密度为2.44%;添加水平在0.10 mg/kg时,回收率范围在87.59%~97.83%之间,相对标准偏差为4.04%。结论采用本法检测人参中二硫代氨基甲酸酯类农药残留量,不仅效率高、数据准确、可靠,而且各项技术指标均满足检测要求。     

Studies on natural repellents against potato tuber moth (Phthorimaea operculella Zeller) in country stores

Summary The effects of the leaves of five plant species, one from each of the generaAmbrosia, Anemone, Eupatorium, Eucalyptus andLantana, on potato tuber moth were investigated under indigenous storage conditions at the Central Potato Research Station, Shillong (1800 m above sea level). Their action was compared with that of a biological insecticide (spores ofBacillus thuringiensis), a chemical insecticide (carbaryl), and an untreated control. The data collected after six months storage on tuber damage, sprout damage and the rotting indicated that the leaves ofLantana aculeata provided most protection to the tubers, reducing damage from over 70% in the check to below 5%, and sprout damage from over 45% to below 3%. Next best wasEucalyptus globulus followed byB. thuringiensis. They may be used on tubers stored for table use or for seed as they had no adverse effect on germination or on the yield of a subsequent crop.     

Comparative Assessment of the Efficacy of Various Nitrogen Fertilizers

Summary

The efficiency of N fertilizers is usually poor; often less than 50% of the applied N is taken up by the crop. This review focuses on various N fertilizers with respect to the significance of different N loss pathways, namely (i) ammonia volatilization, (ii) dinitrogen and nitrogen oxide emissions, and (iii) nitrate leaching. Further, the significance of biological N immobilization, ammonium fixation and, finally, the impact of nitrate vs. ammonium uptake on crop yield are also discussed. The reviewed literature shows that N fertilizers may differ markedly in their susceptibility to losses. There is, however, considerable scope to improve N efficiency of each N source by proper N management practices.     

Pharmacokinetics of Marine-Derived Drugs

Marine organisms represent an excellent source of innovative compounds that have the potential for the development of new drugs. The pharmacokinetics of marine drugs has attracted increasing interest in recent decades due to its effective and potential contribution to the selection of rational dosage recommendations and the optimal use of the therapeutic arsenal. In general, pharmacokinetics studies how drugs change after administration via the processes of absorption, distribution, metabolism, and excretion (ADME). This review provides a summary of the pharmacokinetics studies of marine-derived active compounds, with a particular focus on their ADME. The pharmacokinetics of compounds derived from algae, crustaceans, sea cucumber, fungus, sea urchins, sponges, mollusks, tunicate, and bryozoan is discussed, and the pharmacokinetics data in human experiments are analyzed. In-depth characterization using pharmacokinetics is useful for obtaining information for understanding the molecular basis of pharmacological activity, for correct doses and treatment schemes selection, and for more effective drug application. Thus, an increase in pharmacokinetic research on marine-derived compounds is expected in the near future.     

In vitro antimicrobial activity of different accessions ofSolanum commersonii Dun. from Uruguay

Summary The in vitro antimicrobial activity of extracts from accessions ofSolanum commersonii Dun. collected in the south of Uruguay was investigated against five microorganisms including the pathogenRalstonia solanacearum. A total of 30 extracts corresponding to organic and aqueous extracts were studied. Interestingly, most of the positive results for growth inhibition were againstR. solanacearum. The extracts were also analyzed for the presence of glycoalkaloids and lectins. Six of the ten aqueous extracts showed lectin presence and a wide variation in the type and amounts of glycoalkaloids, was found. Results indicate that there is no clear relationship between the antimicrobial activity against the five microorganisms screened and the presence or amounts of lectins and glycoalkaloids, traditionally regarded as possible antimicrobial metabolites in theSolanum genus, which indicates the presence of as yet unidentified antimicrobial compounds.     

Novel food and non-food uses for sorghum and millets

Sorghum and millets have considerable potential in foods and beverages. As they are gluten-free they are suitable for coeliacs. Sorghum is also a potentially important source of nutraceuticals such antioxidant phenolics and cholesterol-lowering waxes. Cakes, cookies, pasta, a parboiled rice-like product and snack foods have been successfully produced from sorghum and, in some cases, millets. Wheat-free sorghum or millet bread remains the main challenge. Additives such as native and pre-gelatinised starches, hydrocolloids, fat, egg and rye pentosans improve bread quality. However, specific volumes are lower than those for wheat bread or gluten-free breads based on pure starches, and in many cases, breads tend to stale faster. Lager and stout beers with sorghum are brewed commercially. Sorghum's high-starch gelatinisation temperature and low beta-amylase activity remain problems with regard to complete substitution of barley malt with sorghum malt . The role of the sorghum endosperm matrix protein and cell wall components in limiting extract is a research focus. Brewing with millets is still at an experimental stage. Sorghum could be important for bioethanol and other bio-industrial products. Bioethanol research has focused on improving the economics of the process through cultivar selection, method development for low-quality grain and pre-processing to recover valuable by-products. Potential by-products such as the kafirin prolamin proteins and the pericarp wax have potential as bioplastic films and coatings for foods, primarily due to their hydrophobicity.     

La pourriture fongique des tubercules de pomme de terre en atmosphère contrôlée

Résumé Fusarium culmorum et, dans une moindre mesure,F. avenaceum, F. sambucinum, Colletotrichum coccodes etCylindrocarpon sp. ont été isolés de tubercules entreposés en atmosphère contr?lée (AC) et atteints de pourriture grave. Des expériences d'inoculation de tubercules avec 10 espèces ou variétés fongiques et conservation en AC à 8 et 10°C ont montré que: 1) les champignons non pathogènes en atmosphère normale (ex.:Cylindrocarpon sp.) le devenaient en AC, 2) ceux qui étaient faiblement pathogènes en atmosphère normale étaient nettement plus virulents en AC (ex.:F. culmorum), 3) les espèces ou variétés virulentes en conditions d'air normales (Fusarium sulphureum etPhoma exigua var.foveata) ne provoquaient pas de pourriture plus grave en AC et leur activité pouvait même être légérement freinée.

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Summary The extensive rotting of tubers which occurred during storage trials in controlled atmospheres has led to a mycological and pathological study of the rots. The most frequently isolated species wasFusarium culmorum althoughF. avenaceum, F. Sambucinum, Coletotrichum coccodes and aCylindrocarpon sp. were also present. Tubers of cvs Bintje and Ulla were inoculated with 19 isolates of 10 fungal species or varieties associated with rotting of stored tubers (Table 1). The tubers were incubated at 8 or 10°C in normal or controlled (2% O₂:1% CO₂, 2% O₂:6% CO₂, 2% O₂:12% CO₂, 6% O₂:6% CO₂) atmospheres and the extent of rotting was determined a month later (Tables 2 and 3 and Fig. 2). Species which were weakly virulent in a normal atmosphere (variousFusarium spp. andPhoma exigua var.exigua) were clearly more aggressive in the controlled atmosphere and this was especially evident in the case ofF. culmorum. Species ot pathogenic in a normal atmosphere under experimental conditions (Colletotrichum coccodes, Cylindrocarpon sp.,Phoma eupyrena) caused rotting in the controlled atmosphere. The two species which were virulent in a normal atmosphere (F. sulphureum andP. exigua var.foveata) were also virulent in the controlled atmosphere and in some cases the extent of rotting was even less. As a general rule, rotting caused by weakly virulent fungi was greater in both cultivars in the controlled than in a normal atmosphere.

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Zusammenfassung Eine starke F?ulnis von in Kontrotrollierter Atmosph?re gelagerten Kartoffelknollen veranlasste eine mykologische und pathologische Untersuchung. Der am h?ufigsten isolierte Pilz warFusarium culmorum. F. avenaceum, F. sambucinum, Colletotrichum coccodes undCylindrocarpon sp. wurden ebenfalls bestimmt. Neunzehn St?mme von 10 Pilzsorten oder-Arten welche bei Lagerf?ulnis vorkommen (Tab. 1) wurden auf Knollen der Sorten Bintje und Ulla inokuliert. Die Lagerung wurde bei 8 oder 10°C under Normalbedingungen oder kontrollierter Atmosph?re durchgeführt (2% O₂:1% CO₂, 2% O₂:6% CO₂, 2% O₂:12% CO₂, 6% O₂:6% CO₂). Der F?ulnisgrad (Abb. 1) wurde nach einem Monat bonitiert. Die Ergebnisse sind in den Tabellen 2 und 3 dargestellt und in der Abb. 2 illustriert. Unter in Normalbedingungen nur schwach virulente Arten (verschiedeneFusarien undPhoma exigua var. exigua) waren deutlich aktiver in kontrollierter Atmosph?re. Dies was besonders der Fall fürF. culmorum. Pilze, die im Versuch unter Normalbedingungen nicht pathogen waren (Colletotrichum coccodes, Cylindrocarpon sp., Phoma eupyrena), haben unter kontrollierter Atmosph?re Sch?den verursacht. Hingegen werden die beiden unter Normalbedingungen sehr pathogenen Arten (F. sulphureum undP., exigua var.foveata), durch kontrollierte Atmosph?re wenig beeinflusst. Es wurde sogar in einigen F?llen eine gewisse Verringerung des F?ulnisbefalls beobachtet. Ganz allgemein haben die getesteten kontrollierten Bedingungen die Entwicklung der Pilzf?ulnis an beiden Kartoffelsorten gef?rdert, speziell durch Pilzarten, welche unter Normal-bedingungen wenig Sch?den verursachen.

     

Extreme resistance to infection by potato virus X in genotypes of wild tuber-bearingSolanum species

Summary Clones derived from thirty-one different accessions (nineteen of Argentine origin) belonging to eightSolanum species were screened for resistance to infection by potato virus X strain cp (PVX cp) by mechanical inoculation of plantlets that had been micropropagated in vitro. Estimates of PVX multiplication obtained by enzyme linked immunosorbent assay and slot blot nucleic acid hybridization allowed the identification of resistant clones derived from five accessions belonging toS. commersonii S. oplocense, S. sparsipilum andS. tuberosum andigena. Resistant genotypes supported PVX concentrations 5 to 15 times smaller than did the susceptible control cultivar Spunta. Graft inoculation test confirmed the presence of extreme resistance similar to that conferred by the ‘immunity’ gene X¹ (also called RX_act).     

Marine Pharmacology in 2016–2017: Marine Compounds with Antibacterial,Antidiabetic, Antifungal,Anti-Inflammatory,Antiprotozoal, Antituberculosis and Antiviral Activities; Affecting the Immune and Nervous Systems,and Other Miscellaneous Mechanisms of Action

The review of the 2016–2017 marine pharmacology literature was prepared in a manner similar as the 10 prior reviews of this series. Preclinical marine pharmacology research during 2016–2017 assessed 313 marine compounds with novel pharmacology reported by a growing number of investigators from 54 countries. The peer-reviewed literature reported antibacterial, antifungal, antiprotozoal, antituberculosis, and antiviral activities for 123 marine natural products, 111 marine compounds with antidiabetic and anti-inflammatory activities as well as affecting the immune and nervous system, while in contrast 79 marine compounds displayed miscellaneous mechanisms of action which upon further investigation may contribute to several pharmacological classes. Therefore, in 2016–2017, the preclinical marine natural product pharmacology pipeline generated both novel pharmacology as well as potentially new lead compounds for the growing clinical marine pharmaceutical pipeline, and thus sustained with its contributions the global research for novel and effective therapeutic strategies for multiple disease categories.