Study on polychlorinated biphenyl congeners and organochlorine insecticides in Daya Bay

1999年 8月 4日采集了大亚湾次表层水、悬浮颗粒物和表层沉积物并用气相色谱 (电子捕集检测器 )分析了其中 12个多氯联苯 (PCBs)和 18个有机氯农药样品。总PCBs含量 ,水体中介于 91.1～ 135 5 .3ng/L ,沉积物中为 (0 .85～ 2 7.37)× 10 -9;总HCHs含量水体中介于 35 .5～ 12 2 8.6ng/L ,沉积物中则为 (0 .32～ 4 .16 )×10 -9;总DDTs含量在水体中介于 2 6 .8～ 975 .9ng/L ,沉积物中为 (0 .14～ 2 0 .2 7)× 10 -9;而在悬浮颗粒物中均未检出。水体和沉积物中DDT/(DDE +DDD)比值较大 ,表明近期仍有此类化学物质输入大亚湾海域。本研究为大亚湾养殖海区提供难降解有机污染物的现状资料。Samples at sub surface water, suspended particulate matter (SPM) and surface sediment collected from Daya Bay in Aug.4, 1999 have been analysed for 12 polychlorinated biphenyl (PCB) congeners and 18 organochlorine insecticides, using gas chromatography with electron capture detection. Total PCBs levels varied from 91.1 ng/L to 1 355.3 ng/L in water and from 0.85×10 -9 to 27.37×10 -9 (dry weight) in sediment. The levels of total hexachlorocyclohexanes in water varied from 35.5 ng/L to 1 228.6 ng/L, whilst in sediment they ranged from 0.32×10 -9 to 4.16×10 -9 (dry weight). None of the target compounds were detected in SPM. For the sum of dichlorodiphenyltrichloroethanes (DDTs), their levels were in the range 26.8～975.9 ng/L water, and (0.14～20.17)×10 -9 (dry weight) in sediment. The higher ratios of DDT/(DDE+DDD) in water and sediment in showed such chemicals will influx into the bay. Current contamination status of persistent organic pollutants was offered in the aquacultural area of Daya Bay.中国科学院大亚湾海洋生物综合实验站基金资助项目 (S96 0 9);; 广东省创新百项资助项目 (2KB0 6 70 1S

Inhibitory effect of anti-human NRP-1 monoclonal antibody on hepatocellular carcinoma cell line HepG2 and its mechanism in vitro

目的研究抗人神经纤毛蛋白-1(Neuropilin1,NRP-1)单克隆抗体对肝癌Hep G2细胞的生长抑制作用及其机制。方法小鼠腹水法制备抗NRP-1单克隆抗体(NRP-1 m Ab)并用r Protein A亲和柱纯化抗体,间接ELISA检测抗体的滴度水平。Western blot检测NRP-1 m Ab对Hep G2细胞的特异性,细胞免疫荧光和流式细胞术检测NRP-1蛋白在肝癌细胞株Hep G2上的表达,MTT法检测NRP-1 m Ab对Hep G2的生长抑制作用,Western blot检测ERK1/2、P-ERK1/2、Akt、P-Akt蛋白的表达水平。结果 SDS-PAGE和间接ELISA检测纯化的NRP-1 m Ab纯度为95%以上,效价为1×10~(-6);Western blot检测结果显示NRP-1 m Ab可与Hep G2细胞膜上的NRP-1蛋白特异性结合。细胞免疫荧光染色结果显示NRP-1定位于Hep G2细胞膜,流式细胞术结果显示NRP-1蛋白在Hep G2细胞上表达水平较高;MTT法检测结果显示NRP-1 m Ab对Hep G2细胞有生长抑制作用。Western blot检测到在不同浓度NRP-1 m Ab作用下,Hep G2细胞裂解液P-ERK1/2、P-Akt蛋白的条带信号逐渐减弱。结论纯化的NRP-1m Ab能抑制Hep G2细胞的生长,其抑制作用是通过EGF和HGF信号通路实现的。The aim of the experimental is to investigate the inhibitory effect of anti-human nerve cilia protein1(Neuropilin-1,NRP-1) monoclonal antibody(NRP-1 mAb) on hepatocellular carcinoma cell line HepG2 and its mechanism in vitro.Anti-human NRP-1 monoclonal antibody(NRP-1 mAb) was prepared from mouse ascites and purified by rProteinA affinity column assay.The titer of antibody was determined using indirect ELISA assay;the characteristic of NRP-1 mAb binding to NRP-1 was determined using Western blotting;the expression of NRP-1protein in hepatocellular carcinoma cell line HepG2 was determined using immunofluorescence assay and flow cytometry assay.Growth inhibition of HepG2 cells treated with different concentrations of NRP-1 mAb was determined using MTT assay,while Western blotting was used to detect the expression levels of ERK1/2,P-ERK1/2,Akt and P-Akt proteins.The results of SDS-PAGE and indirect ELISA showed that the purity of purified NRP-1mAb was more than 95%and the titer was 1×10~(-6).Western blotting analysis suggested that NRP-1 mAb could bind specifically to NRP-1 on HepG2 cell;immunofluorescence staining showed that NRP-1 was located in the membrane of HepG2 cells.Flow cytometry analysis showed that the expression level of NRP-1 on HepG2 cell was relatively high.Western blotting analysis suggested that P-ERK1/2 and P-Akt expression levels were down-regulated after having incubated HepG2 cells with different concentrations of NRP-1 mAb.In conclusion,NRP-1 mAb could inhibit the growth of HepG2 cells(P<0.05),and its inhibitory effect is achieved by reducing the P-ERK1/2 and P-Akt expression.南京军区医学科技创新项目(12MA061,15MS104

INVESTIGATION OF SALT DAMAGE IN MANGO TREES IN XIAMEN

“叶焦病”是闽南地区芒果（Ｍａｎｇｉｆｅｒａ ｉｎｄｉｃａ Ｌ．）的一种常见病．对不同地点受害植物的叶片及土壤理化指标的分析表明：①土壤酸度、总Ｎ、总Ｐ、Ｋ、Ｎａ等含量与芒果受害程度无关；②受害程度与叶片Ｃｌ、Ｋ含量、３０—４０ ｃｍ土壤Ｃｌ含量及总盐含量呈显著正相关；③造成厦门地区芒果“叶焦病”的主要原因是盐害，其中起主要作用的是Ｃｌ；④芒果是一种对盐比较敏感的植物，土壤总盐含量达０．４８９‰时仍可正常生长，高于此含量则出现受害症状．Leaf scorch in mango (Mangifera indica L.) trees was investigated in March, 1997 in 13 sites at 30-300 m from seashore of Xiamen City. Symptom of leaf scorch in shoot leaves was divided into 6 grades. Soil properties and elements in leaves were tested. The results showed that soil pH and the total N, P, K and Na contents were not related to the leaf scorch damage. The degrees of injury caused by leaf scorch were positively related to the content of Cl and K in leaves and to the Cl and salt contents in soil at 30-40 cm depth. It is concluded that the main factor resulting in leaf scorch is salt, and Cl plays an important role. Mango trees grow normally in soil under 0.489‰ salinity

自组装单层保护金纳米团簇的量子化电容充电

本文研究自组装单层保护金纳米团簇(C12Au MPC)在常温下二氯甲烷溶液中的量子化电容充电效应.示差脉冲伏安曲线显示金核平均直径为2.0 nm的C12Au MPC在-0.6~0.6 V电位区间内有9个明显的量子化电容充电峰,其双电层电容总的变化趋势为在零电荷电位附近最小,随着电位正移或负移电容变大.而且随着该金核尺寸的增大,MPC双电层电容值也变大

小剂量K562 细胞NOD/SCID 小鼠动物模型的建立

【目的】探索建立小剂量( 1×106) 人急性红白血病K562 细胞株的NOD/SCID 小鼠动物模型及通过 流式细胞仪对NOD/SCID 小鼠的肿瘤负荷情况进行评价的可行性。【方法】实验组NOD/SCID 小鼠分别经尾静 脉接种K562 细胞1×106、5×106, 比较不同剂量接种实验组小鼠的生存时间、组织病理改变及通过流式细胞术 对NOD/SCID 小鼠体内的肿瘤标记进行检测。【结果】1×106 及5×106 K562 细胞接种的NOD/SCID 小鼠的生存 时间分别为( 30.3±4.3) d 和(22.2±3.7)d; 其外周血、骨髓及肝、肺组织匀浆中均可发现不同比例的肿瘤细胞; 通 过流式细胞术检测5×106 K562 细胞接种组NOD/SCID 小鼠外周血、肝匀浆中人CD13 表达水平显著高于1× 106 接种组, 而肺匀浆的CD13 表达水平两组无显著性差异。【结论】小剂量( 1×106) K562 细胞NOD/SCID 小 鼠动物模型的建立是完全可行的,这有助于降低实验成本

碱性介质中正丁醇在铂电极上吸附和氧化的电化学原位FTIR反射光谱和EQCM研究

运用电化学循环伏安(CV)、原位FTIR反射光谱和电化学石英晶体微天平(EQCM)等方法研究了碱性介质中正丁醇在Pt电极表面吸附和氧化行为。结果表明:正丁醇电氧化过程与溶液酸碱性有着密切的关系。酸性介质中正丁醇在Pt电极上的CV曲线有2个正向氧化峰,而碱性介质中只有1个正向氧化峰,第2个氧化峰的消失可能是由于碱性介质中Pt电极表面钝化引起的。原位FTIR反射光谱检测到,在实验条件下,碱性介质中正丁醇电氧化过程的最终产物只有丁酸根。EQCM研究还从电极表面质量定量变化的角度提供了正丁醇反应机理的新数据

福建城市化发展战略博士笔谈

2003年5月,“福建省博士创业促进会”在福州举办了福建省城市发展战略“博士月谈”,与会者主要是省内高校和科研单位的专家、博士。会上,大家用书面发表意见,畅所欲言,崇论宏议。本刊精选部分意见,以飨读者。相信这些意见对福建城市化问题研究的深化将起到积极的推动作用

Opportunistic Tendencies,Business Risk and Audit Quality

以行为经济学“前景理论“分析审计行为中存在的机会主义倾向对于审计意见的作用机制,采用深交所数据进行实证检验后发现,经营风险越小的上市公司越容易获得清洁的审计意见。原本应该反映上市公司财务信息质量的审计意见似乎成了财务业绩评价的标准,这说明审计行为中存在着机会主义倾向。在方法上引入行为经济学的基本理论可以拓展审计研究的思路,并在理论上进一步升华我们对于审计行为的认识。According to "Prospect Theory" of behavioral economics,this paper analyzed the mechanism between auditors' opportunistic tendencies and the audit opinions,then examined the hypothesis by the data from Shenzhen Stock Exchange in China.The empirical results showed that the smaller the business risks of listed companies was,the easier to get clean audit opinions.Audit opinions which should have reflected the quality of financial reports just became an evaluation of financial performance,which indicated the existence of opportunistic tendencies in the audit action.This study introduced behavioral economics into audit research not only to extend the methodological thought but also to sublimate our knowledge of audit action.国家自然科学基金资助项目(70872106);江苏省社科基金资助重点项目(09GLA001

基于PLC及Ethernet的发射机控制系统改造

根据高频发射机远程控制的要求,设计了一种基于工业以太网和PLC的高频发射机远程控制系统,采用STEP7和Wincc分别进行PLC程序设计和上位机人机界面设计。重点介绍了系统的硬件配置、网络结构、频率微调、软件设计和系统功能。该系统设计简化了网络结构,提高了系统的可靠性和稳定性