输气管道中缓蚀剂雾化浓度分布及加注量计算

利用液体雾化流动理论，对缓蚀剂在天然气管道内的雾化过程，雾化浓度分布及其保护管道的机理进行了研究。研究中发现，缓蚀剂的雾化在喷流状态下最为充分，且可形成均匀的保护膜；而雾化角、雾化细度、雾化均匀度和浓度分布等评定缓蚀剂雾化质量的，又可以用来检验管道是否得到了有效保护。     

氮素形态在土壤中的转化及对烤烟产量的影响

 试验研究了云南省玉溪地区气候、土壤条件下,铵态氮、尿素施入土壤中的转化,使用硝化抑制剂双氰胺（DCD）研究不同形态氮及其比例对烤烟生长的影响,以及施用秸秆、油饼对烤烟生长的影响。结果表明,施入土壤中的铵态氮、尿素其水解和硝化过程约在施肥后的1个月内完成,土壤中硝态氮含量随时间逐渐下降,1个月后土壤中铵态氮、硝态氨含量都降至痕量水平;硝化抑制剂对铵态氮硝化有显著的抑制效果;铵态氮、硝态氮对烤烟产量没有影响,秸秆、油饼则显著降低烤烟产量。     

Derivation and testing of a model to predict selection for fungicide resistance

A mathematical model was derived to predict selection for fungicide resistance in foliar pathogens of cereal crops. The model was tested against independent data from four field experiments quantifying selection for the G143A mutation conferring resistance to a quinone outside inhibitor (QoI) fungicide in powdery mildew (Blumeria graminis f.sp. hordei) on spring barley (Hordeum vulgare). Fungicide treatments with azoxystrobin differed in the total applied dose and spray number. For each treatment, we calculated the observed selection ratio as the ratio of the frequency of the resistant strain after the last and before the first spray. The model accurately predicted the variation in observed selection ratios with total applied fungicide dose and number of sprays for three of the four experiments. Underprediction of selection ratios in one experiment was attributed to the particularly late epidemic onset in that experiment. When the equation representing epidemic development was modified to account for the late epidemic, predicted and observed selection ratios at that site were in close agreement. On a scatter plot of observed selection ratios on predicted selection ratios, for all four experiments, the 1:1 line explained 89–92% of the variance in the mean of observed selection ratios. To our knowledge, this is the first fungicide resistance model for plant pathogens to be rigorously tested against field data. The model can be used with some degree of confidence, to identify anti‐resistance treatment strategies which are likely to be effective and would justify the resources required for experimental testing.     

蛋白质合成抑制剂对萌发玉米超弱光子辐射的影响

为了揭示种子萌发过程中超弱光子辐射机理,分别采用蛋白质合成的转录抑制剂放线菌素D(actinomyin D,AMD)和翻译抑制剂环己亚胺酮(cycloheximide,CHM)处理萌发玉米种子,研究了玉米萌发过程中鲜质量的变化以及自发光子辐射和外界光诱导的延迟光子辐射的变化。结果表明,50μg/m L的AMD部分抑制了萌发玉米鲜质量的增长,100μg/m L的CHM完全抑制了萌发玉米鲜质量的增长,萌发玉米自发光子辐射强度的增长与种子鲜质量的增长呈现正相关(相关系数r分别为0.95492、0.93218和0.96235)。研究还发现,在玉米萌发过程中,AMD和CHM对延迟光子辐射的增长有不同的抑制作用,CHM部分抑制了延迟光子辐射的初始光子数、相干时间和积分强度的增大,AMD则使初始光子数、相干时间和积分强度不再增加。研究结果为揭示种子萌发过程中超弱光子辐射的机理及其技术开发提供参考。     

厚壁毛竹的主要化学成分及其稀酸水解成分分析

以1年生、2年生和5年生厚壁毛竹的秆、枝、叶为研究对象,对其主要化学组成进行分析;同时对竹粉和综纤维素进行稀硫酸处理,分析其糖及抑制物的浓度。结果表明：随着竹龄和部位的不同,厚壁毛竹的主要化学组成呈现一定的变异规律,叶片的灰分含量最高,秆部灰分含量最低,叶片的苯醇抽提物最高;1年生厚壁毛竹秆部的纤维素含量最高,不同竹龄的厚壁毛竹的综纤维素含量变化不大;5年生厚壁毛竹秆部的酸不溶木质素含量最高,而1年生厚壁毛竹叶片的含量最低;秆的各种糖浓度均大于枝,枝的糖浓度均大于叶;抑制物中乙酸的浓度最高,乙酰丙酸的浓度最低;竹粉中糖含量及抑制物浓度均比综纤维素高。     

Effects of pirenzepine on expression of MMP-2 and TIMP-2 in stroma of sclera in chick myopic eyes

AIM:To observe the effect of intravitreal injection of pirenzepine on form-deprivation myopia in chicks. METHODS:Forty-one day old chicks were randomly divided into 4 groups:normal control group, form deprivation group, vehicle control group and pirenzepine injection group. The right eyes of all chicks were used as experimental eyes. The deprived eyes in vehicle control group and pirenzepine injection group received daily intravitreal injection of vehicle control solution(0.01 mol/L PBS) and pirenzepine(1%in PBS), respectively. Optical examinations such as refraction, axial length and equatorial diameter were made at the end of the 5th day. The mRNA and protein levels of matrix metalloproteinase 2(MMP-2) and tissue inhibitor of metalloproteinase-2(TIMP-2), and the activity of MMP-2 were detected by RT-PCR, Western blotting and zymography analysis,respectively. RESULTS:Refraction, axial length and equatorial diameter of the eyes in pirenzepine injection group were significantly lower than those in form deprivation group and vehicle control group(P<0.05), but those were higher(P<0.05) and the eyes were relatively myopic as compared with normal control group. The mRNA expression, protein le vels and activity of MMP-2 in pirenzepine group were significantly higher than those in normal control group(P<0.01), and were significantly lower than those in form deprivation group and vehicle control group(P<0.01, P<0.01). The mRNA and protein levels of TIMP-2 in pirenzepine group were significantly lower than those in normal control group(P<0.01), and was significantly higher than those in form deprivation group and vehicle control group(P<0.01, P<0.01). CONCLUSION:Intravitreal injection of pirenzepine may partly prevent form-deprivation myopia by modulating the expression of MMP-2 and TIMP-2 in the fibrous layer of sclera.     

不同蛋白酶抑制剂对绿僵菌侵染东亚飞蝗的影响

为了揭示不同蛋白酶抑制剂对绿僵菌致病力的影响,明确绿僵菌经消化道侵染东亚飞蝗的作用机制,采用分光光度法测定了经绿僵菌IPPM202及不同蛋白酶抑制剂处理后,不同时间东亚飞蝗中肠总蛋白酶、类胰蛋白酶、类胰凝乳蛋白酶、乙酰胆碱酯酶（AchE）和谷胱甘肽硫转移酶（GSTs）活力的动态变化。结果表明,绿僵菌IPPM202处理后10 d内,东亚飞蝗中肠总蛋白酶活性呈现先上升再下降再上升的趋势,类胰蛋白酶活性呈先上升再下降趋势,类胰凝乳蛋白酶活性逐渐上升;但两种解毒酶的变化均为先上升后下降。加入两种抑制剂后,总体上抑制了东亚飞蝗中肠总蛋白酶和两种解毒酶的活性,降低了菌株IPPM202的侵染力,其中,甲苯磺酰基-L-氨基联苯氯甲基酮（tosyl-L-phenylalanine chloromethyl ketone,TPCK）作用较对脒苯基甲磺酰氯（4-amidino phenyl methane sulfonyl fluoride,APMSF）更加显著,使各种酶活力降低至与对照无差异水平。本研究对于揭示绿僵菌在中肠的致病机理及寄主对真菌侵染的免疫机制有一定的指导意义。     

氯苯醚酰胺(Y13149)生物活性初步研究及水稻纹枯病菌对其敏感性基线的建立

氯苯醚酰胺[N-(2-(2,4-二氯苯氧基)苯基)-3-(二氟甲基)-1-甲基-1H-吡唑-4-酰胺,Y13149]是由华中师范大学基于药效团连接碎片虚拟筛选策略(PFVS)快速发现的新型琥珀酸脱氢酶抑制剂类(SDHIs)化合物。采用菌丝生长速率法,测定了该创制化合物的农药生物活性。结果表明:氯苯醚酰胺对真菌具有较广的抗菌谱,对供试10种植物病原真菌均具有较好的抑制活性,EC50值在0.008~15.25 mg/L之间,其对立枯丝核菌的抑制活性最强,但对辣椒疫霉和链状腐霉活性较弱。田间试验表明,氯苯醚酰胺对水稻纹枯病具有较好的防治效果,有效剂量75 g/hm2时的平均防效为79.6%,其防效总体略好于噻呋酰胺(75 g/hm2的平均防效为77.3%)。此外,氯苯醚酰胺对采自浙江和江苏两省的125株水稻纹枯病菌的EC50值分布在0.002~0.259 mg/L之间,且呈近似正态单峰曲线,平均EC50值为(0.021 ±0.008) mg/L,因此可将其作为水稻纹枯病菌对氯苯醚酰胺的敏感性基线,用于田间抗药性监测。     

鱼类肝脏酯酶的同工酶构成及其对磷酸三苯酯和马拉氧磷的敏感性

用聚丙烯酰胺凝胶电泳法分离了麦穗鱼 (Pseudorasbora p arva)、金鱼 (Carassius auratus)、尼罗罗非鱼 (Tilapja nilotica)、食蚊鱼 (Gambusia affinis)、虹鳟 (Salmo gairdneri)等五种鱼的肝脏酯酶的同工酶 ,以乙酸α-萘酯为底物测定了它们的活性。在麦穗鱼、金鱼、尼罗罗非鱼体内发现两条酶带 ,在食蚊鱼和虹鳟体内发现一条酶带。离体抑制率实验表明 ,五种鱼肝脏内均含有对磷酸三苯酶敏感的酶带 ,而对马拉氧磷敏感的酶带只存在于麦穗鱼、金鱼、尼罗罗非鱼体内。酯酶同工酶分布型的意义及与马拉硫磷选择毒性的关系在本文中进行了讨论。