板栗土壤中微量营养元素地球化学特征

同时采用有效态和欧共体BCR(the Community Bureau of Reference)三步提取法对0-20 cm和20-40 cm土层中Ca,Mg,Fe,Zn,Cu,Mn进行形态分析,探索燕山山区板栗土壤中微量营养元索活性、形态分布特征和迁移能力.结果表明.栗粮间作会影响板栗对营养元素的吸收,且两层土壤中各元素活性相差不大;板栗纯林中0-20 cm土层的Cu,Zn活性明显高于20-40 cm土层;淋溶褐土和褐土性土两种土壤亚类,不同栽培制度对微量营养元素在板栗土壤中的形态分布特征影响不大.Cu,Zn,Fe主要以残渣态存在,Mn主要以可还原态和残渣态存在.且弱酸提取态高于其它元素.板栗土壤中元素的迁移能力排序为:Ca>Mg>Mn>Cu>Zn>Fe.     

Resistance tests and field trials with bromadiolone for the control of Norway rats (Rattus norvegicus) on farms in Westphalia, Germany

BACKGROUND: The aim of this study was to determine the incidence and the level of resistance to bromadiolone among rats on farms suspected of being foci of resistance by using the international normalised ratio (INR)‐based blood clotting response (BCR) test. Whether the level of reduced susceptibility constitutes ‘practical resistance’ was subsequently determined in field trials. RESULTS: The 2.5 multiple of the ED₅₀ baseline was used to test for the incidence of resistance, and higher multiples in the range of the suspected resistance factor were used to investigate the degree of resistance. The ED₅₀ values of bromadiolone in resistant rats were confirmed in the range 4.70–7.05 mg kg^?1 for males and 4.62–6.61 mg kg^?1 for females. Variations within these ranges appeared between farms. According to the BCR resistance tests, 50–100% of rats were classified as resistant prior to the field trials; 29–100% of rats survived the treatments. CONCLUSION: BCR tests based on the use of the INR and baselines are suitable for determining the incidence and for assessing the level of resistance in populations of Norway rats. The majority of rats of the Westphalian resistant strain, characterised by the Y139C marker in VKOR, are resistant to bromadiolone under practical control conditions. Copyright © 2011 Society of Chemical Industry     

镉污染土壤生物质炭修复的化学稳定机制

以不同生物质炭添加量修复稻田土壤为研究对象,采取三步连续提取法对3年来土壤中镉元素的形态分布特征及其变异规律进行了系统分析。结合土壤理化性质,探讨了镉污染稻田生物质炭修复的化学稳定机制。结果表明,在生物质炭修复2、3年后,与对照相比土壤pH分别提高了0.16～0.65单位和0.26～0.60单位;土壤有机质分别提高了26.2%～50.4%和29.2%～51.2%;镉的赋存形态由有效态向潜在有效态或无效态转变,酸溶态分别降低了5.9%～37.6%和21.7%～27.3%;40 t/hm2处理强度土壤镉的氧化态和残渣态分别升高了126.7%和64.2%,显著降低镉污染的生物可利用性和生态毒性。该研究结果能够为深入探讨生物质炭修复机制提供理论依据,并且为生物质炭在重金属污染土壤中的农业应用提供技术支撑。     

香港土壤研究Ⅶ.BCR提取法研究重金属的形态及其潜在环境风险

基于类型土壤的重金属元素形态分析研究相对较少,本研究以香港地区7个亚纲的土壤剖面为例,利用欧共体参比司(BCR)制定的三步连续提取法研究了类型土壤中重金属Cd、Cu、Pb和Zn的化学形态及其潜在环境风险。结果表明,Pb、Cd和Zn元素除残留态外,HOAc溶解态的比例也相对较高,但不同类型的土壤有所差别,而Cu元素则以残留态和可氧化态为主。在这7种类型土壤中,正常潜育土和湿润淋溶土中的重金属潜在环境风险相对较高,而在这4种重金属元素中,又以Pb元素的潜在环境风险最大。     

FAK shRNA inhibits growth of leukemic cell line BCR/ABL-BaF3

AIM: To investigate the effect of focal adhesion kinase (FAK) shRNA on the growth of leukemic cells.METHODS: Lentiviral-FAK-shRNA was transfected into BCR/ABL-BaF3 cells, while empty vector was transfected into the same cells for control. The proteins of FAK and other molecules were detected by Western blotting. Cell growth was observed by culturing the leukemic cells in RPMI-1640 medium in vitro, and colony formation was observed by culturing the leukemic cells in methylcellulose medium. To establish a murine model of leukemia, BCR/ABL-BaF3 cells were injected into BALB/c mice through tail vein. Survival time of the leukemic mice was monitored, and the distribution of the leukemic cells in spleen of the mice was also detected. RESULTS: FAK shRNA inhibited the protein expression of FAK, reduced STAT5 phosphorylation and induced caspases-3 activation in BCR/ABL-BaF3 cells. FAK shRNA inhibited the cell growth in vitro. Colony formation experiment showed that the number of colony in vector control group and FAK shRNA group was 215.60±13.01 and 125.00±9.06, respectively, and the difference was statistically significant (P<0.01). The mice in vector control group died between day 21 and day 27, while the mice in FAK shRNA group died between day 52 and day 60, and the difference was statistically significant (P<0.05). Moreover, 25 days after injection of leukemic cells, the percentage of leukemic cells in spleen of the leukemic mice in vector control group and FAK shRNA group was (82.40±6.13)% and (14.50±3.70)%, respectively (P<0.01). CONCLUSION: FAK shRNA inhibits the growth of leukemic cells in vitro and in vivo, indicating that FAK gene silencing might be a new therapeutic strategy for leukemia.     

BCR法在污染农田黑土重金属形态分布研究中的应用

通过对东北地区污染农田黑土剖面的取样调查分析，对重金属Cd、Ph、Cu、Zn在农田黑土中的污染状况及其迁移特征进行了对比研究，并就BCR（the Community Bureau of Reference）连续提取法在农田土壤重金属污染评估中的应用进行了探讨。结果表明，重金属的迁移率大小依次为：Cd〉Cu〉Pb〉Zn，Cd的酸可溶态占全量的比率高于其它重金属。Pb的酸可提取态浓度随土壤深度增加而增大，公路附近土壤中PL、Cu及城市郊区土壤中Cd、Pb和Zn的氧化物结合态含量均随土壤深度的增加而升高，已存在向下迁移的趋势。4种重金属有机结合态在采样区土壤中基本都表现为耕层高于非耕层。研究表明，应用BCR连续提取法有助于确定土壤重金属污染以及重金属向下迁移状况，借助该法可以有效、可靠地对土壤重金属污染进行评估。     

化学萃取修复尾渣土壤的金属形态变化特征

The efficiency of EDTA, HNO3 and CaCl2 as extractants to remove Pb, Zn and Cu from tailing soils without varying soil pH was investigated with distributions of Pb, Zn and Cu being determined before and after extraction using the sequential extraction procedure of the optimized European Community Bureau of Reference （BCR）. Results indicated that EDTA and HNO3 were both effective extracting agents.The extractability of extractants for Pb and Zn was in the order EDTA 〉 HNO3 〉 CaCl2, while for Cu it was HNO3 〉 EDTA 〉 CaCl2. After EDTA extraction, the proportion of Pb, Zn and Cu in the four fractions varied greatly, which was related to the strong extraction and complexation ability. Before and after extraction with HNO3 and CaCl2, the percentages of Pb, Zn and Cu in the reducible, oxidizable and residual fractions changed little compared to the acid-extractable fraction. The lability of metal in the soil and the kinds of extractants were the factors controlling the effects of metal extraction.     

淹水条件下有机肥对土壤重金属形态转化及迁移的影响

采用土柱模拟试验,利用欧共体参比司提出的BCR连续提取法,探讨了重金属Zn,Cu,Pb,Cd在农田土壤中的化学形态及迁移风险。结果表明,施用不同有机肥对重金属向下迁移影响不大,淹水9个月后,Zn,Cu,Pb,Cd从表层土壤（0-20 cm）向下迁移了约2 cm,集中于20-22 cm土层,不易对深层土壤造成污染。添加有机肥后,0-10 cm土层中Zn,Cu,Pb,Cd的酸溶态比例随着淹水时间的增加而降低,而可还原态比例却随之升高,表明有机肥对重金属的有效性有一定的抑制作用。在此期间,可氧化态和残渣态的含量基本保持不变,两者百分比之和在各元素中均小于15%。     

Establishment of a human chronic myeloid leukemia-like mouse model

AIM：To establish a new model of chronic myeloid leukemia (CML) for further studying the pathogenesis mechanisms and discovering new therapeutic targets of this disease. METHODS：The retroviral packaging technique was improved by increasing retroviral titer with higher-quality plasmid, better cell state and appropriate cell seeding density for further studying. Donor BALB/c mice were pretreated with 5-fluorouracil (5-FU), and their bone marrow cells were infected with p210 BCR/ABL retroviral supernatant (BCR/ABL group) or empty retroviral vector (MigR1) supernatant (MigR1 group). Infected bone marrow cells were transplanted into lethally irradiated recipient BALB/c mice via tail vein. The activities of the mice were observed after bone marrow transplantation (BMT). The morphology of peripheral blood cells and bone marrow cells, and the pathological changes of the liver and spleen in dying mice were also determined. RESULTS：Retroviral packaging efficiency was improved by optimizing the experimental conditions with higher-quality plasmid, better cell state and appropriate cell seeding density. All mice in BCR/ABL group died at 19 to 25 d after BMT. Their myelocytes, metamyelocytes and mature granulocytes in peripheral blood and bone marrow were abundant. Hepatosplenomegaly and granulocyte infiltration in the liver and spleen were also observed. All mice in MigR1 group were normal. CONCLUSION: We have successfully set up a mouse model of CML by increasing retroviral titer with improved retroviral packaging technique, transfecting BCR/ABL into mouse bone marrow cells in vitro and transplanting the cells to the recipients of the same lineage.     

污泥中重金属的环境活性及生态风险评估

研究了湖南省长沙市、株洲市和常德市10个污水处理厂剩余污泥中As,Cd,Cu,Ni,Pb,Zn的含量和形态特征,并利用潜在生态危害指数法对污泥农用过程中重金属的生态风险进行了综合评价。结果表明,城市污泥中富含有机质及N,P,K等养分,然而,污泥表现为以Cd为主的多金属污染,不能直接农用。污泥中Cd含量为1.43～260mg/kg,以可还原态为主,占全量比例高于28.9%;As,Pb的可还原态,Ni,Zn的酸可溶态和可还原态,Cu可还原态和氧化态所占比例较高,表明污泥中重金属的潜在环境活性较高。风险指数评价结果表明,污泥中Cd和As是潜在的强生态风险元素;以工业废水处理为主的污水处理厂污泥重金属单因子生态风险相对较高,且综合潜在生态风险严重。