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泥蚶血红蛋白的制备及其抗菌活性研究 总被引：3，自引：2，他引：1
利用凝胶层析技术从泥蚶血细胞裂解物中分离纯化得到两种血红蛋白,回收率为74.3%,并通过Tricine-SDS-PAGE和质谱技术鉴定为Tg-HbⅠ(同源二聚体)和Tg-HbⅡ(异源四聚体)。分别通过琼脂扩散法和分光光度法测其抗菌活性和过氧化物酶活性,结果发现,两种Tg-Hb对大肠杆菌和恶臭假单胞杆菌均有抗菌活性,Tg-HbⅡ对于恶臭假单胞菌和大肠杆菌的MIC值分别为0.063mg/mL和0.13mg/mL,Tg-HbⅠ对两种菌的MIC均为0.048mg/mL;两种Tg-Hb均具有过氧化物酶活性,能催化愈创木酚、邻苯二酚、对苯二酚、苯酚、左旋多巴等多种酚类物质。在Tg-Hb中添加GSH后,两种Tg-Hb均不再对恶臭假单胞杆菌具有抗菌活性。可见,两种Tg-Hb对恶臭假单胞杆菌等的抗菌活性均是通过其过氧化物酶活性发挥作用的。 相似文献
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苯并(a)对大弹涂鱼肝脏抗氧化防御系统影响的初步研究 总被引：10，自引：0，他引：10
苯苯并并（（ａａ））芘芘((ＢＢａａＰＰ))是是一一种种具具强强致致癌癌性性的的多多环环芳芳烃烃,,广广泛泛存存在在于于受受污污染染的的海海洋洋环环境境中中。。早早期期对对苯苯并并（（ａａ））芘芘的的研研究究主主要要集集中中于于苯苯并并（（ａａ））芘芘暴暴露露与与终终反反应应—————癌癌变变的的发发生生或或肿肿瘤瘤的的形形成成之之间间的的相相关关性性研研究究。。近近年年来来,,通通过过对对苯苯并并（（ａａ））芘芘在在动动物物体体内内的的代代谢谢过过程程及及其其致致毒毒机机理理的的研研究究,,发发现现苯苯… 相似文献
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Simple prediction methods are proposed to estimate the wave induced pressures on smooth impermeable seawalls. Based on the physics of the wave structure interaction, the sloped seawall is divided into a total of five zones (zones 1, 2 and 3 during run-up (corresponding pressures are called as positive pressures) and zones 4 and 5 during run-down (corresponding pressures are called negative pressures)) (Fig. 1). Zone 1 (0<z<d−Hi/2), where the wave pressure is governed by the partial reflection and phase shift; Zone 2 (d−Hi/2<z<d), where the effect of wave breaking and turbulence is significant; Zone 3 (d<z<Run-up height), where the pressure is induced by the run-up water; Zone 4 (Run-down<z<d), where the wave pressure is caused by the run-down effect and Zone 5 (0<z<d-Run down), where the negative wave pressures are due to partial reflection and phase shift effects. Here d is the water depth at the toe of the seawall, Hi is the incident wave height and z is the vertical elevation with toe of the seawall as origin and z is positive upward. For wave pressure prediction in zones 1 and 5, the empirical formula proposed by Ahrens et al. (1993) to estimate the wave reflection and Sutherland and Donoghue's recommendations (1998) for the estimation of phase shift of the waves caused by the sloped structures are used. Multiple regression analysis is carried out on the measured pressure data and empirical formulas are proposed for zones 2, 3 and 4. The recommendations of Van der Meer and Breteler (1990) and Schüttrumpf et al. (1994) for the prediction of wave run-down are used for pressure prediction at zone 4. Comparison of the proposed prediction formulas with the experimental results reveal that the prediction methods are good enough for practical purposes. The present study also shows a strong relation between wave reflection, wave run-up, wave run-down and phase shift of waves on wave pressures on the seawalls. 相似文献
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采用组织化学和分光光度技术对贻贝(Mytilus edulis)发育早期酯酶(Esterase,EST)和过氧化物酶(Per-oxidase,POD)活性进行了研究,以探讨贝类早期发育过程中的免疫防御机制。EST和POD均存在于贻贝的卵母细胞、胚胎和幼虫中,但在各个发育时期的分布和含量不同。组织化学定位结果表明,从卵母细胞到D型面盘幼虫各个发育时期的胚胎和幼虫均呈EST强阳性和POD阳性;卵母细胞核区较大且颜色较浅;桑椹期开始出现不同细胞阳性的强弱差异;原肠胚、担轮幼虫和D型面盘幼虫细胞间阳性强弱的差异逐步增大。分光光度测定结果表明,α-醋酸酯酶活力,卵母细胞最低,受精卵略有提高,卵裂期胚胎提高较大且达最高峰,囊胚、原肠胚和担轮幼虫又逐渐下降,D型面盘幼虫下降较大;α-丁酸酯酶活力,卵母细胞较高,受精卵略有提高且达到最高峰,卵裂期胚胎到D型面盘幼虫各个时期逐渐下降,D型面盘幼虫最低。不依赖卤素POD活力,卵母细胞最低,受精卵提高较大,囊胚达到最高峰,原肠胚、担轮幼虫和D型面盘幼虫逐渐降低。依赖卤素POD活力与不依赖卤素POD活力的变化规律相似,但受精卵提高较小,而卵裂期提高较大。EST和POD可能在贻贝的发育早期抵抗病原微生物侵染方面发挥重要作用。 相似文献