Growth inhibition and oxidative stress in two species of marine diatoms exposed to 1-phenylethanol

1-phenylethanol (1-PEA) is a flavor extensively used in the production of cosmetics, beverages, and food. The release of 1-PEA into coastal environments has aroused great concern. However, its potential effects on marine organisms are still unknown. In order to provide a better understanding of the ecological risks of 1-PEA in marine environments, this study determined the toxic effects of 1-PEA on two marine diatoms (Phaeodactylum tricornutum and Skeletonema costatum). The diatoms were grown in culture medium containing different concentrations of 1-PEA for 96 h. The contents of chlorophyll a, chlorophyll c, glutathione (GSH), malondialdehyde (MDA), and the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), were measured at the end of the exposure period. 1-PEA was shown to significantly inhibit the growth of diatoms, with 96-h EC50 values of 257.14 mg/Land 126.46 mg/L in P. tricornutum and S. costatum, respectively. In P. tricornutum, the levels of SOD, CAT, GPx, GSH, and MDA were stimulated only when 1-PEA concentrations were close to or greater than the 96-h EC50 value. However, in S. costatum, the activities of SOD and CAT, and the syntheses of two chlorophylls were inhibited even at an exposure concentration below the 96-h EC50 value. Taken together, these findings indicate a potential ecological risk by discharging 1-PEA into coastal areas and its species-specific toxic effects on marine organisms.     

纳米塑料和二氧化钛食相暴露对凡纳滨对虾血细胞功能及抗氧化系统的影响

纳米塑料和纳米金属氧化物粒子在不同领域的使用量日益增多,这些纳米材料进入水生系统可能带来的相关环境风险引起了人们的关注.本文通过食相暴露,分析了100 nm纳米聚苯乙烯(PS)和纳米二氧化钛(TiO2)暴露对凡纳滨对虾(Litopenaeus vannamei)的血细胞功能和氧化还原平衡的干扰.实验组对虾分别投喂混有2...     

麻痹性贝毒对肝脏和肾脏氧化损伤的影响

为了探讨麻痹性贝毒(PSP)对肝脏和肾脏损伤的机制,采用膝沟藻毒素GTX-1,4对小鼠进行急性暴露,剂量为1μg/kg,时间分别为60、90、120min。结果发现,与对照组相比,肝脏染毒组中的还原型谷胱甘肽(GSH)含量没有显著变化;在肾脏中,60 min时染毒组GSH含量没有明显变化,90、120 min时GSH含量降低;两器官中抗氧化酶(GSH-Px、SOD)活性与对照组相比均无显著变化(P0.05)。从而推断,GSH参与了PSP对肾脏损害的毒性过程;肾中GSH含量有可能作为PSP早期检测的敏感指标。     

PM2.5降尘对A549细胞线粒体氧化损伤的影响

将不同浓度PM_(2.5)降尘作用于A549细胞后,利用MTT法检测其存活率,W-G染色观察细胞形态,荧光探针法检测细胞ROS和MMP相对水平,以探讨PM_(2.5)降尘对A549细胞线粒体氧化损伤的影响及作用机制。结果显示,经12. 5μg/m L的PM_(2.5)降尘作用A549细胞3 h后,细胞存活率为(81. 77±6. 15)%,并随作用浓度及时间增加呈递减趋势。PM_(2.5)染毒后可观察到细胞形态不规则,胞膜溶解破坏,细胞微核出现。PM_(2.5)降尘作用于细胞24 h后,胞内ROS相对含量随暴露浓度增加呈递增趋势,细胞MMP相对水平随染毒浓度增加而降低,且胞内ROS和MMP两者间存在显著相关关系(R2=0. 878)。提示PM_(2.5)降尘处理A549细胞后可通过刺激ROS的产生,诱导细胞MMP下降,造成细胞线粒体氧化损伤。     

A simulation experimental study on oxidative kinetics of sphalerite under hypergene condition

The sphalerite oxidative kinetics under hypergene condition was simulated and studied by means of a mixed flow reactor over a pH range of 1.0 7.8,and at dissolution temperatures from 20 to 55℃,ferric ion concentrations from 1.0×10-5 to 1.0×10-2 mol/L,O 2 flux of 0.5 L/min,and oxidants of ferric ion and O 2.It is indicated that with ferric ion as oxidant,the oxidation rate of sphalerite increases with increasing ferric ion concentration,temperature and decreasing pH value,and under the studied conditions,the dissolution rates of Zn and Cd are approximately identical,with the values of activation energy being 41.75 and 42.51 kJ·mol-1,respectively,suggesting that the oxidation rate of sphalerite is controlled by chemical reactions on mineral surface.However,with O 2 as oxidant,the oxidation mechanism of sphalerite varies with pH value.Oxidation rate decreases with increasing pH value when pH is lower than 5.95,whereas the increase of pH value results in an increase in oxidation rate when pH value is higher than 7.The oxidation rate of sphalerite can be expressed as:R Zn =10 1.1663 [Fe3+] 0 0.154 ·[H+] 0.2659 ·e-41.75/RT or R Cd =10 1.7292 [Fe3+] 0 0.170 ·[H+] 0.2637 ·e-42.51/RT     

Effects of Environmental Cadmium on Cadmium Accumulation,Oxidative Response,and Microelements Regulation in the Liver and Kidney of Hexagrammos otakii

The effects of cadmium(Cd)on metal accumulation,microelements contents,and antioxidant responses in Hexagram-mos otakii were studied.The fish were exposed to 0.2,2.5,or 10μg L?1 Cd for 12 or 24 days.Then,the concentration of Cd and mi-croelements(Ca,Fe,Zn,and Se)were determined in the liver and kidney.Moreover,the activities of antioxidant enzymes including superoxide dismutase(SOD),catalase(CAT),and glutathione-S-transferase(GST),and the content of malondialdehyde(MDA)in the liver and kidney were also measured.A continuous accumulation of Cd was observed throughout the experimental period.Cd accumulation was higher in liver than that in the kidney,while Ca and Fe contents were lower in liver than those in the kidney.Cd exposure resulted in a decrease of Ca and Fe concentrations in the kidney,while there was no effect on the liver.Zn and Se remained unaffected with exposure to Cd.Cd exposure induced severe oxidative stress in H.otakii,as indicated by significant induction of the activities of SOD,CAT,and GST,and a simultaneous increase of MDA content.These data show that antioxidant enzymes and mi-croelements contents can be used as potential biomarkers to monitor environmental health in fish.     

军曹鱼(Rachycentron canadum)幼鱼对环境低氧胁迫氧化应激与能量利用指标的响应

本文探究环境低氧对军曹鱼(Rachycentron canadum)氧化应激和能量利用指标的影响,为军曹鱼的健康养殖提供参考依据。通过设置低氧胁迫–恢复实验,将军曹鱼幼鱼(平均体质量(220.67±20.73)g)在低氧((2.64±0.25)mg/L)胁迫3 h及复氧((6.34±0.15)mg/L)8 h、24 h和48 h后,测定其肝脏和肌肉组织的氧化应激与能量利用指标。结果显示,低氧胁迫后,肝脏中丙二醛(Malondialdehyde,MDA)、过氧化氢酶(Catalase,CAT)和谷胱甘肽还原酶(Glutathione Reductase,GR)活力均显著低于对照组(p<0.05),乳酸脱氢酶(Lactate Dehydrogenase,LDH)活性显著高于对照组(p <0.05);肌肉中MDA和脂质过氧化物(Lipid Peroxidase,LPO)活性均显著低于对照组(p<0.05),超氧化物歧化酶(Superoxide Dismutase,SOD)和LDH活性均显著高于对照组(p<0.05);肌糖原和肝糖原含量极显著低于对照组(p<0.0...     

北京西北城区一次重污染过程中PM10的氧化损伤能力研究

为评估大气重污染期间北京市可吸入颗粒物(PM_(10))的毒性,采集2016年3月份一次大气重污染过程中北京市大气PM_(10)样品,应用质粒DNA损伤评价法来研究其氧化损伤能力。结果表明,雾霾期间PM_(10)对DNA的损伤率高于雾霾逐渐消退时期,远高于雾霾前期清洁天,颗粒物对DNA损伤率随剂量的增加而增加。雾霾前后PM_(10)水溶样品的平均TD_(20)值表现为雾霾前清洁天(788.01μg/mL)雾霾消退后期(470.40μg/mL)雾霾期间(55.78μg/mL),说明氧化能力雾霾期间雾霾消退后期雾霾前清洁天。另外通过雾霾前后数据对比得到,暴露毒性指数TI大小顺序为雾霾期间(13 245.06)雾霾消退后期(1 658.87)雾霾前清洁天(254.08),说明雾霾期间PM_(10)对人体危害更大。     

不同煤化程度煤热解过程中汞释放规律

采用热重与测汞仪联用技术,对5种不同煤化程度的煤进行氧化热解实验,研究不同煤化程度煤的热解过程及煤中汞的释放规律。结果表明：X射线衍射（XRD）曲线中衍射峰的特征可反应煤化程度,衍射峰的高度越高,宽度越窄,煤化程度就越高。不同煤化程度的煤在氧气中热解,质量损失随煤化程度的加深而增大,且随着煤化程度的加深,氧化热解的起始温度、最大热分解温度、终止温度也逐渐升高。随着煤化程度的升高,煤中汞释放所需的时间逐渐增加,且汞释放最大值所对应的热重（TG）曲线热解率最大的温度随煤化程度的加深而升高。     

Comparison in copper accumulation and physiological responses of Gracilaria lemaneiformis and G. lichenoides (Rhodophyceae)

Heavy metal pollution has become a worldwide problem in aquaculture. We studied copper (Cu2+ ) accumulation and physiological responses of two red algae Gracilaria lemaneiformis and Gracilaria lichenoides from China under Cu2+ exposure of 0-500 μg/L in concentration. Compared with G. lemaneiformis, G. lichenoides was more capable in accumulating Cu2+ , specifically, more Cu2+ on extracellular side (cell wall) than on intracellular side (cytoplasm) and in cell organelles (especially chloroplast, cell nucleus, mitochondria, and ribosome). In addition, G. lichenoides contained more insoluble polysaccharide in cell wall, which might promote the extracellular Cu2+ -binding as an efficient barrier against metal toxicity. Conversely, G. lemaneiformis was more vulnerable than G. lichenoides to Cu 2+ toxin for decreases in growth, pigment (chlorophyll a, chlorophyll b, phycobiliprotein, and β-carotene) content, and photosynthetic activity. Moreover, more serious oxidative damages in G. lemaneiformis than in G. lichenoides, in accumulation of reactive oxidative species and malondialdehyde, and in electrolyte leakage, because of lower antioxidant enzyme (superoxide dismutase and glutathione reductase) activities. Therefore, G. lichenoides was less susceptible to Cu2+ stress than G. lemaneiformis.