镉、硒胁迫下华贵栉孔扇贝消化腺差异蛋白表达

【目的】应用蛋白组学技术解析镉（Cd）、硒（Se）胁迫对华贵栉孔扇贝（Chlamys nobilis）组织中蛋白表达的影响,为扇贝金属蓄积和耐受机制研究提供数据。【方法】将华贵栉孔扇贝置于分别含有Cd、Se、Cd+Se的海水中,采用非标记定量Label-free蛋白组学技术分析对照组和处理组扇贝消化腺的差异表达蛋白（differentially expressed proteins,DEPs）,并对其进行GO富集、KEGG通路富集和蛋白质相互作用网络分析。【结果】CT组的闭壳肌和外套膜中的Cd质量分数显著高于鳃、性腺和消化腺（P <0.05）。除闭壳肌外,在镉、硒、Cd+Se胁迫下扇贝其他组织中的Cd或Se质量分数均显著增加（P <0.05）。Se+Cd胁迫下扇贝闭壳肌、外套膜和消化腺中的Se质量分数显著降低（P <0.05）,说明扇贝中Se和Cd相互拮抗。共鉴定出887个DEPs;与对照组相比,Se组45个上调蛋白、9个下调蛋白,Cd组15个上调蛋白、10个下调蛋白,CdSe组13个上调蛋白、3个下调蛋白。生物信息学分析发现,Cd、Se胁迫的DEPs主要涉及参与细胞...     

用改进单纯形优化法测定大米中的镉

利用原子吸收分光光度法（火焰法）,根据改进单纯形优化法建立了大米中微量元素镉的测定方法,结果表明,改进单纯形优化法的灵敏度比传统方法有所提高,实验次数少,线性关系良好。运用法对广东省韶关马坝、英德、增城、广州效区等地区出产生的大米进行了测定,并用标准加入法做回实验,回收率介于９４．６６％－１０３．３０％。     

超声波锌(卷)-镉法测定天然水中的硝酸盐

硝酸盐的测定方法很多,目前常采用镉－铜法和锌－镉法［２］。镉－铜法还原率高,无盐误差,为目前国际上公认的测定硝酸盐的标准方法［３］,但测定速度较慢,还原柱的前处理工作较为繁琐。锌－镉法测定硝酸盐简便快速,但其还原享受盐度影响很大,在淡水中其还原率仅为２０％左右。于志刚等［１］发现锌－镉法在盐度１０～７５时还原率保持恒定为７４％,从而采取向样品中加入固体海盐的方法来消除盐误差,获得较好结果。但该方法存在的问题是振荡采用往复式振荡器,体积庞大不适合现场操作。作者采用超声波振荡法,并对试验条件进行了改…     

重金属对扁额细首纽虫金属硫蛋白的影响

生物体内金属硫蛋白含量变化,可作为环境中重金属污染的生物标志物.通过暴露实验研究了扁额细首纽虫Cephalothrix simula暴露在不同浓度的铜,锌和镉溶液96 h,其体内金属硫蛋白含量的变化规律.结果表明3种重金属离子的胁迫作用均导致金属硫蛋白含量增加,在实验初期(6～24 h),金属硫蛋白含量达到高峰;金属硫蛋白含量与暴露溶液金属浓度具有明显的剂量～效应关系,金属离子浓度越高,金属硫蛋白含量越高;锌离子诱导金属硫蛋白合成的作用大于铜、镉离子.     

Effects of heavy metals （Pb^2＋ and Cd^2＋） on the ultrastructure, growth and pigment contents of the unicellular cyanobacterium Synechocystis sp. PCC 6803

The unicellular cyanobacterium Synechocystis sp. PCC 6803, a model organism known for its unique combination of highly desirable molecular genetic, physiological and morphological characteristics, was employed in the present study. The species was cultured in BG11 liquid medium contained various initial concentrations of Pb²⁺ and Cd²⁺ (0, 0.5, 1, 2, 4, 6 and 8 mg/L). The experiment was conducted for six days and the metal induced alterations in the ultrastructure, growth and pigment contents were assessed. Alterations in the ultrastructure of the Synechocystis sp. PCC 6803 cells became evident with the increased (>4 mg/L Pb²⁺) metal concentration. The photosynthetic apparatus (thylakoid membranes) were found to be the worst affected. Deteriorated or completely destroyed thylakoid membranes have made large empty spaces in the cell interior. In addition, at the highest concentration (8 mg/L Pb²⁺), the polyphosphate granules became more prominent both in size and number. Despite the initial slight stimulations (0.2, 3.8 and 6.5% respectively at 0.5, 1 and 2 mg/L Pb²⁺), both metals inhibited the growth in a dose-dependent manner as incubation progressed. Pigment contents (chlorophyll α, β carotene and phycocyanin) were also decreased with increasing metal concentration. Cells exposed to 6 mg/L Pb²⁺, resulted in 36.56, 37.39 and 29.34% reductions of chlorophyll α, β carotene and phycocyanin respectively over the control. Corresponding reductions for the same Cd²⁺concentrations were 57.83, 48.94 and 56.90%. Lethal concentration (96 h LC₅₀) values (3.47 mg/L Cd²⁺ and 12.11 mg/L Pb²⁺) indicated that Synechocystis sp. PCC 6803 is more vulnerable to Cd²⁺ than Pb²⁺. Supported by the Chinese Scholarship Council     

重金属镉对拟柱孢藻(Cylindrospermopsis raciborskii)PSII及能量分配特征的影响效应

为了研究重金属镉对藻类光合系统毒性效应及能量分配特征,以拟柱孢藻(Cylindrospermopsis raciborskii)为研究对象,分析了不同镉浓度下拟柱孢藻的生长、单位叶绿素a含量、光合系统Ⅱ(PSⅡ)叶绿素荧光及其能量分配模型.结果表明:不同浓度镉培养拟柱孢藻96 h后,0.2 mg/L Cd~(2+)对拟柱孢藻单位细胞叶绿素a含量及PSⅡ活性无显著影响,而0.5mg/L Cd~(2+)培养时拟柱孢藻的单位细胞叶绿素a含量为对照组的62.97%.当Cd~(2+)浓度高于5 mg/L时,拟柱孢藻的PSⅡ活性受到抑制并导致表征量子产额分配的φEo和ψo分别下降了15.35%和13.52%.此外,当Cd~(2+)浓度高于5 mg/L时,藻体PSⅡ能量分配表现为TRO/CSm和ETO/CSm显著减小,DIO/CSm差异不显著,类囊体能量分配表现为ABS/RC、TRO/RC和DIO/RC显著增大,明显区别于0.2、0.5和1 mg/L Cd~(2+)处理组.这些结果表明PSⅡ反应中心是镉对拟柱孢藻光合作用影响的重要作用位点,且Cd~(2+)高于5 mg/L时显著影响了拟柱孢藻PSⅡ反应中心并且抑制了PSⅡ电子传递链供体侧的电子传递,而拟柱孢藻则可能通过改变PSⅡ的能量分配来保护和缓解镉对其光合结构的损伤.     

Enrichment and mobility of cadmium and other heavy metals in the area of the Three-Gorges Reservoir

This study focused on the geochemical distribution patterns and ecological effects of Cd and other heavy metals such as As, Hg, Cr, Cu, Ni, Pb, and Zn in rock, soil, water, sediment and crops in the area of the Three-Gorges Reservoir within Chongqing, and aimed at the protection of ecological environment and rational application of the local lands. This study found that the metals of Cd, Hg and Pb presented pollution in the surface environment along the Yangtze River, that is Cd〉Hg〉Pb （Cu）〉Zn〉As〉Ni〉Cr. The pollution of Cd in sediment was mainly attributable to the regional black shales, and partly to the urban sewage and garbage. The geochemical modes of metals in the sediment varied. Cr, Hg, Ni, and Pb mainly existed as residues, and Cd as carbonate. Cd exited as a high proportion in the modes of ion-exchange, carbonate, and iron-manganese oxidation, up to 63 percent. The contents of heavy metals in soiland sediment were correlated to the host clay minerals, such as illite, montmorillonite, kaolinite and chlorite. It is shown that Cd was transported with clay minerals in the Yangtze River over long distance and formed the regional anomaly. In the abnormal area of Jianping in Wushan County, higher Cd contents are reported in the local crops and local villagers＇ hairs than from the background areas.     

广东仁化凡口铅锌矿西矿带矿石中主要伴生组分的研究

本文是笔者研究凡口铅锌矿西矿带矿石中伴生组分的成果。指出方铅矿与闪锌矿不仅是工业利用矿物，而且是伴生元素的载体矿物。银主要赋存在方铅矿中，其次于闪锌矿中，以深红银矿，银黝铜矿等独立矿物产出。闪锌矿是镉、汞、锗、镓等元素的载体矿物，汞以小于０．００２ｍｍ粒度的辰砂形式存在于闪锌矿中。铅、锌、银、镉、汞、锗、镓等元素的含量可作储量计算依据。     

土壤Cd污染对甘蓝光学显微成像特征的影响

在不同浓度CdNO_3的土壤中栽培甘蓝,应用光学相干层析成像系统(OCT)对甘蓝不同生长时期的叶片进行检测。结果显示:土壤中Cd含量较低时OCT值有降低的趋势,表明Cd对甘蓝植物的种子萌友与生长有一定的促进作用;而Cd浓度高于100mg/kg时,OCT值持续升高,表明Cd对甘蓝植物的种子萌发与生长均起到强烈的抑制作用,并且后期的累积作用对甘蓝叶片组织造成一定的损害。     

西安市街道灰尘中铬、镉、铅赋存状态及环境效应

本文通过对街道灰尘中铬、镉、铅三种元素赋存状态研究、铬、铅在街道灰尘中以残渣态为主，镉以有机质结合态为主。虽然铬、铅、镉存在形式稍有差异，但其在街道灰尘中主要以矿物质的形态存在，说明其比较稳定，不易迁移转化，对环境的危害比较持久。在治理措施上应有早遏止微量元素向环境中排放，以免其与灰尘发生相互作用对环境造成长期的危害。