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991.
溶藻胶弧菌脂多糖对大菱鲆白细胞吞噬活性的影响 总被引:1,自引:0,他引:1
针对溶藻胶弧菌脂多糖在增强大菱鲆非特异性免疫功能、提高机体抗病能力方面的作用机理,开展了研究工作。实验中以浓度为2.4mg/ml 溶藻胶弧菌脂多糖,通过口服和注射的方式接种平均体重47.2g 大菱鲆幼鱼,接种后第7、15、 30天,分别采血根据血细胞吞噬作用检测结果计算吞噬百分比和吞噬指数。结果显示,溶藻胶弧菌脂多糖对白细胞吞噬活性有明显促进作用,在增强白细胞的吞噬能力方面作用不显著。 相似文献
992.
993.
研究了在重金属镉胁迫条件下,大弹涂鱼(Boleophthalmuspectinirostris)肝脏黄嘌呤氧化酶活性的变化。重金属镉胁迫12h时0·5mg/LCd2 组XOD酶活性和对照组比较显著升高(P<0·05);胁迫24h时,大弹涂鱼0·05mg/LCd2 组肝脏的XOD酶活性和对照组比较极显著升高(P<0·01),而0·5mg/LCd2 组酶活性结果却降低;恢复3d时0·5mg/LCd2 又极显著升高(P<0·01)。在镉胁迫解除5d时,3个浓度组的酶活性均极显著降低(P<0·01),其中0·05mg/LCd2 组和0·5mg/LCd2 组的酶活性和对照组酶活性比较无显著差异(P>0·05),5mg/LCd2 组的酶活性极显著低于对照组的酶活性(P<0·01)。实验结果表明,大弹涂鱼肝脏黄嘌呤氧化酶活性对水体中镉污染敏感,有可能用做海洋环境污染的生物标记。 相似文献
994.
Chronically cannulated rainbow trout were exposed in acid water (pH 4.0) for 72h. The gill potential was strongly dependent on water pH, being blood side negative in neutral water, but positive in acid water. Catecholamine levels increased irregularly during acid exposure, and the Bohr and Root effects were not completely erased by the effect of catecholamines during acid exposure. Long term exposure to low water pH, although causing an acidosis in the fish, did not suppress resting oxygen consumption. Prolonged exposure to acid conditions, however, resulted in an increase in ammonia excretion. Changes in plasma sodium and chloride were similar to that reported previously for trout exposed to low calcium, acid water. We conclude that exposure of trout to pH 4 soft water, although impairing oxygen transport, does not limit resting oxygen consumption but does reduce the scope for activity. More extreme acid conditions do impair resting oxygen uptake. 相似文献
995.
棉酚对鲤鱼急性中毒的研究 总被引:4,自引:0,他引:4
鲤鱼(体重约16克)腹腔注射乙酸棉酚0,7.3,54,100,200,400mg/kg体重,经四天(96小时)后,死亡率分别是0,0,20%,70%,90%,100%。96小时半数致死剂量是63.6mg/kg体重。注射剂量高于54mg/kg体重时,发生腹腔红肿、体壁溃烂,甚至死亡。实验结果说明虽然棉籽水平的棉酚不引起鲤鱼的任何可见的中毒症状,但是腹腔注射大剂量棉酚可引起与哺乳类相似的中毒症状。 相似文献
996.
蔬菜产业是湖南农业的重要组成部分,是集经济效益、社会效益和生态效益为一体的产业。蔬菜产业集群式发展有利于提高资源利用效率,提升蔬菜产业的整体竞争力。新形势下为保持湖南省蔬菜产业集群的良好发展态势和促使其健康发展,通过产业集群理论联系实际分析了湖南蔬菜产业集群发展现状,并针对产业集群式发展中面临的问题提出了有利于产业集群稳健发展的新思路。 相似文献
997.
A Brett-type respirometer was used to measure the effect of water pH on swimming performance of rainbow trout (Salmo gairdneri). Variations in water pH between 6 and 9 had no measurable effect on maximum aerobic swimming speed. At water pH 4, 5, and 10, however, the critical velocity was only 55, 67, and 61% respectively of that recorded for fish in water of pH 7. Exposure to acid conditions increased coughing and breathing frequency. Acid exposure resulted in a decrease whereas alkaline exposure resulted in an increase in both whole blood and red blood cell pH. Blood gas and acid-base characteristics showed little change during swimming at 2.0 BL/second, but exhaustive swimming resulted in a marked and immediate drop in blood pH in fish in acid, alkaline and neutral water. The blood acid-base status was restored to resting levels after exercise in neutral and alkaline water, but the acidosis was maintained following exercise in acid water. Fatigue occurred earlier and blood lactate levels increased to a higher level in fish swum to exhaustion in acid or alkaline water, compared with fish in neutral water. 相似文献
998.
Ultra high molecular weight polyethylene (UHMWPE) containing benzophenone (BP) is photocrosslinked under continuous UV irradiation. BP addition as low as 0.77 mol% per repeating unit of UHMWPE is enough to increase the gel fraction up to 99.8 %. The crosslinks are formed through the recombination of methine radicals generated from the hydrogen abstraction of UHMWPE by the excited BP. The heat of fusion of UHMWPE reduces substantially and the peak decomposition temperature increases as much as 15.8 oC due to the crosslinked network, coupled with slight decrease in crystallinity. The tensile strength, modulus and toughness of the crosslinked UHMWPE film are significantly improved with increasing crosslinking density. The wear rate of the UHMWPE also remarkably decreases from 10.2 mg/million cycles to 1.9 mg/million cycles, which can minimize the wear of total hip joint anthroplasty bearings. 相似文献
999.
1000.