镉对单环刺螠非特异性免疫及组织蓄积的影响

为探究镉(Cd)对海洋动物的毒性效应,考察了不同质量浓度(0.005、0.05和0.5 mg·L~(-1)) Cd处理对单环刺螠相关免疫生理指标及主要组织中Cd蓄积量的影响。结果表明:Cd胁迫下,血细胞密度(density of hemocyte, DHC)先升后降再升,酚氧化酶(phenoloxidase, PO)活力先升后降,溶菌酶(lysozyme, LSZ)活力先降后升再降,至处理96 h,处理组DHC均显著高于对照组(P0.05),总蛋白含量变化不显著;除低浓度胁迫组(0.005 mg·L~(-1))PO活力与对照组相近外,其他处理组的PO和LSZ活力均显著低于对照组(P0.05)。超氧化物歧化酶(superoxide dismutase, SOD)活力和丙二醛(malondialdehyde, MDA)含量总体呈上升趋势,过氧化氢(H_2O_2)含量先升后降再升,至胁迫96 h,各处理组SOD活力、MDA和H_2O_2含量均显著高于对照组(P0.05)。总之,Cd胁迫对单环刺螠非特异性免疫影响显著,Cd的短期胁迫可刺激DHC、PO和LSZ升高,免疫力增强,而高浓度Cd的胁迫时间较长会造成机体解毒能力下降,持续刺激机体产生过氧化反应,MDA含量升高,可作为单环刺螠在Cd长期胁迫下的免疫检测指标。不同胁迫浓度组单环刺螠肌肉和消化道中的Cd含量随胁迫时间均呈上升趋势,且存在显著的时间-剂量-效应关系(P0.05),其蓄积量水平为:消化道肌肉,具有组织特异性。     

磷酸三苯酯(TPP)和磷酸三(2-氯异丙基)酯(TCPP)诱导人胚肾细胞HEK293凋亡的机制研究

磷系阻燃剂对人体的潜在毒性作用引起了国内外研究者的广泛关注。肾脏是机体重要的排毒器官,若肾脏细胞受损,可能影响肾脏功能的正常发挥。本研究以人胚肾细胞HEK293为研究对象,结合传统毒理学实验,筛选出磷酸三苯酯(TPP)及磷酸三(2-氯异丙基)酯(TCPP)诱导人胚肾细胞HEK293凋亡的关键靶标基因p53。在此基础上采用分子对接模拟和光谱法分析发现,TPP和TCPP分别以嵌插方式和沟槽方式结合p53-DNA,改变基因片段的框架结构,启动分子起始事件,通过影响相关基因(Bax、Hrk、Bcl-2和Bad)的表达量,导致线粒体途径释放cyt c,最终激活Caspase 7实现细胞凋亡。研究结果阐明了此类污染物诱导凋亡的作用机制,为毒害化学品的污染防控提供理论依据。     

Distribution and assessment of mercury (Hg) in surface sediments of Futian mangrove forest,China

Environmental Geochemistry and Health - To investigate the distribution of mercury (Hg) in Futian mangrove wetland, surface sediments from land to sea were collected, including Kandelia obovata,...     

Electro-remediation of tailings from a multi-metal sulphide mine: comparing removal efficiencies of Pb,Zn, Cu and Cd

Sulphidic mine tailings characterised by high concentrations of heavy metals (Pb 3532?±?97?mg/kg, Zn 8450?±?154?mg/kg, Cu 239?±?18?mg/kg and Cd 14.1?±?0.3?mg/kg) and abundant carbonate (17%) were subjected to eight lab-scale electrodialytic remediation (EDR) experiments to investigate the influence of current density, treatment time and particle size on removal efficiency. Pb and Cu removal improved when increasing current density, while Zn and Cd removal did not. In contrast Zn and Cd removal improved by grinding the tailings, while Pb and Cu removal did not. At the highest current density (1.2?mA/cm²), 94%, 75%, 71% and 67% removal of Pb, Zn, Cu and Cd could be achieved, respectively, on grinded tailings in 28 days. Sequential chemical extraction made before and after EDR revealed larger oxidisable fractions of Zn, Cu and Cd, representing large fractions of sulphides, which was likely to be the main barrier to be removed as efficiently as Pb. This was in accordance with acid/base extraction tests in which Pb showed high solubility at both high and low pH (up to 65% and 86% of extraction, respectively), while considerable extraction of Zn (55%) happened only at low pH; and very limited extraction (<20%) of Cu and Cd occurred at any pH.     

Phosphorus adsorption by functionalized biochar: a review

Environmental Chemistry Letters - Phosphorus is essential element for agricultural production, yet phosphorus ore resources are non-renewable and become depleted. Moreover, phosphate release from...     

Contamination characteristics of trace metals in dust from different levels of roads of a heavily air-polluted city in north China

Concentrations of eight trace metals (TMs) in road dust (RD) (particles?<?25 μm) from urban areas of Xinxiang, China, were determined by inductively coupled plasma mass spectrometry. The geometric mean concentrations of Zn, Mn, Pb, As, Cu, Cr, Ni and Cd were 489, 350, 114, 101, 60.0, 39.7, 31.6, and 5.1 mg kg^?1, respectively. When compared with TM levels in background soil, the samples generally display elevated TM concentrations, except for Cr and Mn, and for Cd the enrichment value was 69.6. Spatial variations indicated TMs in RD from park path would have similar sources with main roads, collector streets and bypasses. Average daily exposure doses of the studied TMs were about three orders of magnitude higher for hand-to-mouth ingestion than dermal contact, and the exposure doses for children were 9.33 times higher than that for adults. The decreasing trend of calculated hazard indexes (HI) for the eight elements was As?>?Pb?>?Cr?>?Mn?>?Cd?>?Zn?>?Ni?>?Cu for both children and adults.     

Characteristics analysis of near-field and far-field aerodynamic noise around high-speed railway bridge

Environmental Science and Pollution Research - The aerodynamic noise around the high-speed railway bridge is studied by the train-bridge-flow field numerical model and theory analysis. With the...     

Structural and technological determinants of carbon intensity reduction of China’s electricity generation

Environmental Science and Pollution Research - Electricity generation is the largest sector with decarbonization potential for China and the world. Based on the new emission factors, this paper...     

Removal of ammonia nitrogen from water by mesoporous carbon electrode–based membrane capacitance deionization

Environmental Science and Pollution Research - The removal of ammonia nitrogen from wastewater is always a focus in current water treatment. In this study, a combination of mesoporous carbon...     

Numerical model of aerobic bioreactor landfill considering aerobic-anaerobic condition and bio-stable zone development

Environmental Science and Pollution Research - Aeration by airflow technology is a reliable method to accelerate waste biodegradation and stabilization and hence shorten the aftercare period of a...