Effect of bovine seminal plasma on bovine endometrial epithelial cells in culture

The purpose of this study was to investigate the effect of seminal plasma (SP) from bulls of known fertility on bovine endometrial epithelial cells (bEEC) in culture. The bEEC from passage 5, approximately 5.0–13 × 10⁵ cells per flask, were challenged with SP from bulls of high or low fertility (n = 3 and 2, respectively) or PBS (control), at 1% (75 μl) or 4% (300 μl) and were incubated for 72 hr (n = 13 per challenge). Total cell number and viability of bEEC after challenge with 1% SP from either high‐ or low‐fertility bulls (75H or 75L, respectively) did not differ from controls. In contrast, challenge with 4% of SP from high‐ or low‐fertility bulls (300H or 300L) negatively affected bEEC cell number and viability. Challenge with 300 L had a greater adverse effect than 300H. These results suggest that the negative effect of bovine SP on bEEC is both dose‐dependent and fertility‐dependent.     

杀菌剂对玉米穗腐病菌的毒力及毒素产生的影响

为筛选防治玉米穗腐病同时减少病原菌毒素积累的化学药剂,采用菌丝生长速率法、涂布平板法分别测定了4种药剂多菌灵、百菌清、吡唑醚菌酯和氰烯菌酯对玉米穗腐病的3种主要致病镰孢菌拟轮生镰孢菌、层出镰孢菌和禾谷镰孢菌菌丝生长和孢子萌发的影响,并采用高效液相色谱法测定了4种药剂对其毒素积累的影响。结果表明:层出镰孢菌菌株127-1和禾谷镰孢菌菌株125-3的最佳产毒时间为第10天。供试4种药剂对3种镰孢菌菌丝生长的EC50值范围为0.18~5.71μg/m L,对孢子萌发的EC50值范围为0.02~8.14μg/m L,均表现出一定的抑制作用。但对3种镰孢菌产伏马毒素、玉米赤霉烯酮和脱氧雪腐镰孢菌烯醇的影响不尽相同,吡唑醚菌酯浓度在1~500μg/m L时能够抑制拟轮生镰孢菌和层出镰孢菌产生伏马毒素,氰烯菌酯能够在0.05~0.8μg/m L浓度范围内显著抑制禾谷镰孢菌产生玉米赤霉烯酮,当多菌灵浓度为0.05~0.5μg/m L时,几乎可以完全抑制禾谷镰孢菌产生脱氧雪腐镰孢菌烯醇。     

黑缘红瓢虫成虫人工饲料研究

黑缘红瓢虫人工饲料研究结果表明：以草鱼肉、鲜猪肝、夜蛾幼虫粉为主要配方的人工饲料基本满足成虫的营养需要．存活率较高，但平均单头雌虫产卵量较低。各配方饲养的黑缘红瓢虫成虫对朝鲜球坚蚧捕食功能反应均符合模型。以有取食刺激因子的配方成虫对朝鲜球坚蚧作用数据，但各饲料配方饲养的成虫捕食能力(1～31头)都随饲养时间(由第25～290天)的延长而减弱；成虫寻找效应(0．3802～0．0717)随着朝鲜球坚蚧密度(2～10头)的增加而下降，以有取食刺激因子的配方成虫对朝鲜球坚蚧的寻找效应较高，但各配方成虫都随饲养时间的延长而减弱。添加取食刺激因子的人工饲料对提高其成虫的越冬存活率、产卵量、捕食能力和寻找效应有明显促进作用．并且其成虫对饲料的利用率和转化率较高。     

拖拉机电液助力转向系统的研究

设计了一种用于拖拉机的电控液压自动助力转向(EHPS)系统,将方向盘阻力转矩引入到系统中,实现了转矩感应型助力特性的液压助力转向,既可保证转向轻便性,确保实时提供足够助力,又减少能量损失。基于AMESim软件建立了EHPS系统仿真模型,分析结果表明系统具有良好的控制精度和快速响应特性。     

Biochemical effects of acute phoxim administration on antioxidant system and acetylcholinesterase in Oxya chinensis (Thunberg) (Orthoptera: Acrididae)

The study was undertaken to evaluate the effects of different concentrations of phoxim on acetylcholinesterase (AChE) and esterase (EST) activities, and antioxidant system after topical application to Oxya chinensis. The results showed that phoxim inhibited AChE activity, and did not cause significant changes in the EST activity and the levels of malondialdehyde (MDA) and reduced glutathione (GSH). After phoxim administration, superoxide (SOD) and catalase (CAT) activities showed a biphasic response with an initial increase followed by a decline in their activities. Glutathione reductase (GR) and glutathione peroxidase (GPx) activities were inhibited in comparison with the control. Glutathione S-transferase (GST) activity showed irregular changes. Its activity increased significantly at the concentrations of 0.06 and 0.12 μg/μL and decreased at the concentrations of 0.09 and 0.24 μg/μL compared with the control. Changes in SOD, CAT, GST, GPx, and GR activities indicated that phoxim caused oxidative damage in O. chinensis. However, no significant changes in MDA content suggested that these enzymes played important roles in scavenging the oxidative free radicals induced by phoxim in O. chinensis. The formation of oxygen free radicals might be a factor in the toxicity of phoxim.     

增施磷钾对马铃薯提质增产的效果

在马铃薯生长发育过程矿质元素通过参与促进同化物的合成、转运和分配,对马铃薯生长发育及产量形成有重要作用[1].同薯8号每生产Ⅰ t鲜薯吸收N、P、K分别为4.38 kg、0.79 kg、6.55 kg,其中以钾吸收量最大[2].丽水市是浙江省马铃薯主产区之一,马铃薯栽培有良好的基础.但在当地农业生产中由于偏施氮肥,磷、钾肥施用量少,至使土壤中氮、磷、钾比例失调,制约了马铃薯生产.本试验通过对马铃薯高产施肥措施的研究,为马铃薯栽培合理施肥提供依据.     

不同密度和施肥量对党参品质及其病害程度的效应研究

针对影响党参等级、浸出物、农残、重金属和病害率的栽植密度和施肥量二因素,采用2因素8水平3重复随机区组法进行研究。结果表明,一等品比例较小且集中于60万株/hm2处理;二等品所占比例最大的是90万株/hm2和360 kg/hm2组合。二等品总额中,施肥量相同条件下,所占比例大小顺序是60万株/hm2＞90万株/hm2＞75万株/hm2＞105万株/hm2处理;所有产品以三等品为主;浸出物全部高于标准值,大于70.0%的有4个组合;在密度相同条件下,As、Cu含量最大值基本都在360 kg/hm2施肥量下产生;Pb最大值则在0施肥下产生;Cd基本都趋近于0.01%;Hg含量规律性不强。根病害率最低的是75万株/hm2和360 kg/hm2组合,为1.48%。密度和施肥量科学合理的配置不仅对品质有重要意义,而且也有助于提高商品性。     

表面油流法显示螺旋离心泵内部流动的研究

对螺旋离心泵叶轮、进水节和进水节与蜗壳交界处的部分端面做了表面油膜、油点试验。通过流谱分析，揭示了表面奇点、分离线与再附着线等流动特征，研究了螺旋离心泵内部流动规律，进而提出了改进螺旋离心泵结构的设想。     

黄鳍鲷肝细胞体外培养研究

以黄鳍鲷肝脏细胞为材料 ,研究其肝细胞体外培养适宜的 p H、血清浓度、谷氨酰胺等条件 ,并进行传代培养试验。结果表明 ,培养液为 :MEM含 2 0 %小牛血清、15 g/ L L-谷氨酰胺及 p H 6 .9～ 7.1时 ,在 2 3℃中静置培养 ,黄鳍鲷肝细胞生长良好 ,3～ 5 d长满单层 ,细胞主要为成纤维细胞状 ,并能顺利传代。细胞动力学试验表明 :传代细胞 1～ 2代为适应期 ,3～ 5代为旺盛期 ,6代之后表现出衰老现象     

压燃机燃用醇-柴混溶燃料的性能研究

乙醇是一种从植物、农业废弃物等转化的再生性能源。应用这种能源的深远意义在于:农业生产者本身也可以成为非石油制品燃料的生产者。 本文详细阐明了压燃机燃用醇—柴混溶燃料所具有的动力性、经济性、燃烧过程、排放烟度、低速扭矩特性、工作噪声等以及改善这些特性的方法与效果。 试验表明:通过合理的调整(供油体积和喷油提前角)和进气温度的控制,未经任何改装S—195型压燃机可以燃用含醇量为17％的混溶燃料,并获得与燃用纯柴油相当的性能指标。