基于扫描电化学显微镜技术评价镉诱导MCF-10A细胞产生的过氧化氢水平

本研究利用扫描电化学显微镜（SECM）技术在生理条件下对人正常乳腺上皮细胞（MCF-10A）受氯化镉刺激的形态变化和活性氧物种（ROS）释放情况进行了实时检测.结果表明,MCF-10A细胞在低浓度或短时间的氯化镉刺激下呈现收缩防御模式;但受到高浓度或长时间的氯化镉刺激时,细胞对氯化镉毒性的防御能力降低,细胞内氧化还原平衡态受到破坏,造成严重的氧化损伤.并利用荧光探针DCFH-DA法证实了扫描电化学显微镜技术检测结果的正确性和可靠性.此外,通过对镉作用下细胞内还原型烟酰胺腺嘌呤二核苷酸磷酸（NADPH）氧化酶,超氧化物歧化酶（SOD）,过氧化氢酶（CAT）及谷胱甘肽（GST）活性的测定,进一步分析了金属镉诱导MCF-10A细胞的氧化应激机制.     

环球扫描

<正>《美国国家地理》2015年5月4日特斯拉助垃圾车电动化跑车、运输卡车,甚至连公共汽车都已经有自己的电动系列了,然而有一种特殊的汽车却一直未能摆脱对化石燃料的依赖—老式垃圾车。今年夏天,加州北部的17辆垃圾车将首次采用电力作为驱动力,该批垃圾车同时还会内置一个备用的柴油发电机。单从外观看来,     

日本公司每日扫描员工笑脸

据英国《每日电讯报》报道，日本东京的京滨急行电铁公司将使用一种“笑容扫描”软件，根据面部特征、嘴唇弧度、眼球运动、皱纹深浅等指标，对人的笑容进行扫描和分析。经过分析后，软件将对人的笑容等级进行打分，从0分到100分，100分为一个人能展露的最大笑容。     

环球扫描

云南师范大学、纽约大学和北努力住完成了年代学、形态学、首次以多学科证据证明中国东北地区是人类最早驯化牛类动物的地区之一，改写了之前学术界普遍认为中东地区是全球动物驯化单—源地的传统观点。对动物驯化起源地和历史的系统认识是了解。     

环球扫描

<正>《自然》2014年10月22日新加坡科学家最近发现绿茶中的一种有效成分——EGCG——能够作为潜在的纳米载药系统用于输送蛋白药物以治疗癌症。一直以来,EGCG都只被认为是绿茶中的一种有益成分,而它能够治疗癌症的功能则是最近才被发现的。研究人员将EGCG和聚乙二醇结合起来,使得EGCG能够保护蛋白质药物不被降解。负责这一研究绿茶不仅养生,还可治癌     

A comparative study and evaluation of sulfamethoxazole adsorption onto organo-montmorillonites

Three organo-montmorillonites were prepared using surfactants, and their adsorption behaviors toward sulfamethoxazole（SMX） were investigated. The surfactants used were cetyltrimethyl ammonium bromide（CTMAB）, 3-（N,N-dimethylhexadecylammonio） propane sulfonate（HDAPS） and 1,3-bis（hexadecyldimethylammonio）-propane dibromide（BHDAP）. The properties of the organo-montmorillonites were characterized by X-ray diffraction, scanning electron microscopy and N2adsorption–desorption isotherm measurements. Results showed that the interlayer spacing of montmorillonite was increased and the surface area as well as the morphology were changed. Batch adsorption experiments showed that the surfactant loading amount had a great effect on the adsorption of SMX. The adsorption process was p H dependent and the maximum adsorption capacity was obtained at p H 3 for HDAPS-Mt, while CTMAB-Mt and BHDAP-Mt showed a high removal efficiency at 3–11. The adsorption capacity increased with the initial SMX concentration and contact time but decreased with increasing solution ionic strength.Kinetic data were best described by the pseudo second-order model. Equilibrium data were best represented by the Langmuir model, and the Freundlich constant（n） indicated a favorable adsorption process. The maximum adsorption capacity of SMX was 235.29 mg/g for CTMAB-Mt, 155.28 mg/g for HDAPS-Mt and 242.72 mg/g for BHDAP-Mt. Thermodynamic parameters were calculated to evaluate the spontaneity and endothermic or exothermic nature. The adsorption mechanism was found to be dominated by electrostatic interaction,while hydrophobic interaction played a secondary role.     

Synthesis and characterisation of potassium polytitanate for photocatalytic degradation of crystal violet

Potassium titanate nanostructures were synthesised by hydrothermal treatment of TiO2 （P25） in KOH and H2O2. As-produced powders were characterised by scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, X-ray diffraction, and nitrogen adsorption-desorption methods. Longitudinally-oriented-wire-like structures with a length up to several micrometres and diameters ranging from 10 to 30 nm were obtained. Larger size fibrous nanowires resulting from the hydrotherrnal treatment showed high affinity in adsorbing crystal violet （CV）, which was mainly due to their high surface area. The photocatalytic bleaching of CV solution revealed that the wires are photoactive under ultraviolet light irradiation. Macroporous nanowires are considered as effective adsorbents of CV, capable of photocatalvtic degradation, and they can be easily separated from the solution by settling.     

直接玫红染料降解菌株的分离鉴定及其特性研究

从黄冈市某印染厂生化处理池分离得到一株对直接玫红FR有高效降解作用的菌株HS-M02。研究表明,菌株HS-M02在合成培养基中能降解直接玫红FR作为生长所需的唯一氮源和能源。UV-Vis动态扫描结果表明,在37℃,pH 7.0条件下,HS-M02在24 h内将20 mg/L的直接玫红FR完全降解。扩增HS-M02菌株的16S rDNA保守基因,通过Blast在线分析,运用Mega5.1软件进行菌株系统进化分析,结果表明,菌株HS-M02与菌株Enterococcus faecium DSM 20477的同源性为100%,结合形态观察和生理生化试验,HS-M02鉴定为屎肠球菌(Enterococcus faecium)。进一步研究表明,菌株HS-M02在24 h内对浓度为20 mg/L的活性黑,酸性红GR、直接大红、还原黄GCN等染料降解率均达90%以上,表现出高效广谱染料脱色降解特性,具有潜在的应用研究价值。     

热脱附-稳定化工序对土壤镉稳定化效率的影响

热脱附-稳定化是修复重金属-有机物复合污染土壤的主要工艺。由于热脱附对土壤重金属有“活化”和“固化”的双重作用,因此,热脱附-稳定化工序会影响重金属的稳定化效率。以含镉(Cd)的复合污染土壤为研究对象,从浸出率、形态分布、微观形貌3个层面,分析热脱附-稳定化(T-S)和稳定化-热脱附(S-T)工艺对Cd稳定化效率的影响。结果表明：S-T工艺浸出率(42.26%)低于T-S工艺(52.11%);由于Cd“活化”“固化”与稳定化作用,S-T工艺处置的土壤Cd弱酸提取态和残渣态比例分别是T-S工艺的0.75,1.4倍,形态更趋于稳定分布;电镜扫描(SEM)显示,S-T工艺比T-S工艺处置后土壤颗粒结晶更为显著,说明土壤Cd的稳定化效果更好。     

环球扫描

11月19日,日本气象研究所的一份报告表明,日本气象研究所在研究美国航空航天局卫星的图片后发现,7月上旬,大量空气微粒子从日本九州岛飘至本州岛,而同时期并没有发现从中国飘来的空气微粒子,日本的这一空气污染现象与中国无关。同时,九州岛上的活火山“樱岛”运动频繁,经常喷出大量浓烟。