60 research outputs found
Determination of 24 Trace Level of Rare Earth and Metal Elements in Coastal and Estuarine Seawater by Polymer Complexation-Ultrafiltration Technique and Inductively Coupled Plasma Mass Spectrometry
建立了聚丙烯酸螯合-超滤(PCP-uf)分离富集、电感耦合等离子体质谱(ICP-MS)测定海水中痕量稀土及金属元素的方法。PH值高于7.5时,海水中的稀土离子、Cu2+、Pb2+、Cd2+、CO2+、nI2+等与聚丙烯酸(PAA)形成稳定的高分子螯合物,经超滤截留、硝酸解离后,实现了稀土及金属元素从海水中的分离、富集;采用ICP-MS的全定量数据采集模式、内标校正的标准校正曲线法对待测元素进行定量分析。在优化实验条件下,方法的相对标准偏差(rSd)为1.7%~7.3%,加标回收率为73%~96%;方法的定量下限(lOQS,10σ)为0.23~13.9 ng/l,方法空白为0.09~8.38 ng/l。建立的方法可用于近岸及河口海水中痕量稀土及金属元素的同时测定。A method of polyacrylic acid-complexation and ultrafiltration for matrix modification and inductively coupled plasma mass spectrometry(ICP-MS)was developed for the determination of 24 trace level of rare earth elements(REEs) and metal elements in coastal and estuarine seawater.REEs ions,Cu2+,Pb2+,Cd2+,Co2+,Ni2+ could reacted with polyacrylic acid(PAA) to form stable complexes when the pH value was above 7.5,which could be separated and enriched absolutely after trapped and eluted from the ultrafilter.Full quantitative data collection mode and internal standard calibration curve were used for the ICP-MS determination.Under the optimized conditions,the relative standard deviations(RSDs) were in the range of 1.7%-7.3%,and the spiked recoveries were between 73% and 96%.The limits of quantitation(LOQs,10σ) ranged from 0.23 ng/L to 13.9 ng/L.The method blank ranged from 0.09 ng/L to 8.38 ng/L.The developed method could be applied in the simultaneous determination of REEs and metal elements in coastal and estuarine seawater.厦门大学近海海洋环境科学国家重点实验室自主创新项目(MELRI0703
Simultaneous Determination of Ultra-trace Level of As,Sb,Bi,Ge,Sn and Hg in Coastal and Estuarine Seawater by Chemical Vapor Generation and Inductively Coupled Plasma Mass Spectrometry
建立了化学蒸汽发生(CVg)电感耦合等离子体质谱(ICP MS)同时测定近岸及河口海水中超痕量AS、Sb、bI、gE、Sn和Hg元素的方法。研究了CVg过程中kbH4、盐酸和硫脲的浓度以及样品流速、载气流速、海水样品盐度等对方法分析性能的影响。结果表明,在0.70%盐酸、0.10 g/l硫脲、11.0 g/l硼氢化钾、载气0.40 l/MIn条件下,6种待测元素的信噪比最高。优化实验条件下,AS、Sb、bI、gE、Sn和Hg的质量浓度在0.1~5.0μg/l内呈良好线性,相关系数不低于0.996 6;方法对0.1μg/l加标样品的相对标准偏差(rSd,n=5)为3.9%~8.9%,实际海水样品的加标回收率为89%~112%;方法的流程空白为0.012~0.036μg/l,定量下限(lOQS,10σ)在0.006 7~0.026μg/l之间,可满足近岸及河口海水样品中超痕量元素测定的需要。A chemical vapor generation(CVG) and inductively coupled plasma mass spectrometric(ICP MS) method was proposed for the simultaneous determination of ultra-trace level of As,Sb,Bi,Ge,Sn,and Hg in coastal and estuarine seawater.Effects of operating parameters,including concentrations of KBH4,HCl and thiourea,pump flow rate and carrier gas flow rate on analytical performance were studied.The results showed that good signal to noise(S/N) ratios for all the analysed elements were obtained when 0.70% HCl,0.10 g/L thiourea,11.0 g/L KBH4,and 0.40 L/min carrier gas were used in the CVG procedure.The relative standard deviations(RSDs,n=5) for 0.10 μg/L spiked sample were in the range of 3.9%-8.9%.The spiked recoveries for the seawater samples were between 89% and 112%.The method blanks were in the range of 0.012-0.036 μg/L.The limits of quantitation(LOQs,10σ) for the developed method were obtained between 0.006 7 μg/L and 0.026 μg/L.The method could be applied in the simultaneous determination of As,Sb,Bi,Ge,Sn and Hg in coastal and estuarine seawater.近海海洋环境科学国家重点实验室自主创新项目(MELRI0703
Expression of α-1,6-dextranase from Penicillium minioluteum in P.pastoris
α-1,6-葡聚糖酶是专一作用于α-1,6糖苷键产生小分子葡聚糖的一类水解酶,广泛的运用于制糖工业和啤酒工业中。采用PCr法扩增朱黄青霉(PEnICIllIuM MInIOluTEuM)C12114的α-1,6-葡聚糖酶基因,将其插入毕赤酵母表达载体PPIC9k。经SACI酶线性化电击转入毕赤酵母基因组,构建重组酵母gS115/PPIC9k-dEX。对构建成功的转化子进行1.5%的甲醇诱导表达,在30℃条件下培养7d时酶活达到最大值,为88.35u/Ml。α-1,6-dextranase,which can hydrolyze dextran specifically by cutting off the α-1,6-glycosidic bond to release shorter saccharides,was widely used in many fields such as sugar industry and beer industry.The gene of α-1,6-dextranase(dex)was amplified through PCR by using Penicillium minioluteum C12114 genomic DNA as template.The amplified gene was cloned into vector pPIC9K and the recombinant plasmid pPIC9K-dex was linearzed with Sac I,then transformed into P.pastoris GS115 by electroporation.The positive transformant was induced to express the enzyme with 1.5% methanol for 7 days under the 30℃,and the activity of the enzyme could reach 88.35U/mL.广东省科技计划项
A New Method for the Measurement of Complexation Stability Constant and Average Coordination Number of Metallic Element with Polymer
建立了基于化学平衡理论模型以及凝胶过滤色谱(gfC)-电感耦合等离子体质谱(ICPMS)联用技术的高分子聚合物-金属配合物稳定常数、平均配位数测定新方法。以聚乙烯亚胺(PEI)和Cu2+为例,对形成的PEI-Cu配合物稳定常数、平均配位数进行测定,以0.02 MOl·l-1 HAC-nAAC为流动相,凝胶色谱柱分离大分子PEI-Cu配合物以及Cu的小分子配合物、游离态离子,最后用ICPMS测定不同形态金属元素的浓度;利用建立的化学平衡理论模型,计算PEI与金属离子形成配合物的稳定常数、平均配位数,测得25℃,PH4.1~5.3时,PEI-Cu配合物稳定常数为109.6~1010.7,平均配位数为1.0~1.3。建立的在线分离、测定方法具有快速、准确的特点,为高分子聚合物-金属配合物的研究提供新的技术手段。A new method using gel filtration chromatography(GFC) and inductively coupled plasma mass spectrometry(ICPMS) was developed for the measurement of complexation stability constant and average coordination number of the complex of metallic ion with polymer.As an example,the binding of PEI with Cu2+was shown and investigated.The macromolecular PEI-Cu complex and micromolecular species of Cu (Ⅱ) were firstly separated by a low efficiency GFC column with a mobile phase of 0.02 mol·L-1HAc-NaAc buffer,and then directly introduced into ICPMS for elemental analysis.The results of complexation stability constant and average coordination number characterized by putting the concentration of different species of metallic element into the equations of the novel chemical equilibrium model which was developed in this study.The results shown that the complexation stability constants(KPEI-Cu) were between 109.6and 1010.7and the average coordination numbers(n) were in the range of 1.0~1.3 when pH was changed from 4.1 to 5.3 at 25 ℃.This online,rapid and accurate method of GFC-ICPMS is a novel technique for the research of polymer-metallic complex.厦门大学近海海洋环境科学国家重点实验室自主创新项目(MELRI0703)资助项
浸润性乳腺癌中FosB的表达与超声征象及临床病理的相关性
【目的】分析FosB在浸润性乳腺癌中的表达及临床病理意义,并探讨其与超声征象的相关性。【方法】收集155例浸润性乳腺癌组织、36乳腺癌旁组织及30例正常乳腺组织做为对照,均采用免疫组织化学SP法和超声检测,分析FosB在浸润性乳腺癌中的的表达差异与组织学分级、淋巴结转移、超声征象等的关系。【结果】①FosB在癌旁组织及正常乳腺组织中的表达水平明显高于浸润性乳腺癌组织中的表达(P<0.01)。②FosB在浸润性乳腺癌组织中的高表达与低组织学分级、ER阳性及PR阳性相关(P<0.05),与肿物直径大小、年龄、淋巴结转移、Her2及临床分期无关(P>0.05)。③FosB在存在微钙化或腋窝淋巴结增大的浸润性乳腺癌组织中高表达,差异有统计学意义(P0.05)。【结论】FosB在乳腺癌组织中的表达水平明显低于癌旁组织及正常乳腺组织,其差异表达与组织学分级、ER、PR相关,有助于乳腺癌的鉴别诊断和指导ER/PR相关患者的个性化治疗。FosB在乳腺癌组织中的差异表达还与微钙化、腋窝淋巴结存在一定的相关性,联合超声与FosB能够更加明确的判读浸润性乳腺癌的恶性程度
第十八届美国理论与应用力学大会总结
1会议概况2018年6月5—9日,第18届美国理论与应用力学大会(18th U.S. National Congress of Theoretical and Applied Mechanics, USNCTAM2018)在美国芝加哥召开.本次大会由美国力学国家委员会和中国力学学会联合主办,旨在探讨和交流近四年世界范围内在理论和应用力学领域的基础研究、创新技术的最新进展,吸引了来自世界各地的近千名专家学
Microsphere Pattern Prepared by a "Reverse" Breath Figure Method
通讯作者地址: Xiong, XP (通讯作者), Xiamen Univ, Coll Mat, Dept Mat Sci & Engn, Xiamen 361005, Peoples R China
地址:
1. Xiamen Univ, Coll Mat, Dept Mat Sci & Engn, Xiamen 361005, Peoples R China
电子邮件地址: [email protected] have reported all interesting method, named reverse breath figure, for the preparation of polymeric microsphere patterns. By the same procedure as breath figure, instead of under a humid atmosphere, linear and star-shaped poly(styrene-block-butadiene) copolymers dissolved in solvents such as toluene, trichloroform, and dichloromethane were cast onto the surface of a glass substrate in methanol or ethanol vapor. After the complete evaporation of the solvent, microspheres with the diameters ranging from hundreds of nanometers to several micrometers were prepared. The microsphere patterns are the reverse of the honeycomb porous structure of breath Figure. The mechanism of the microsphere formation has been studied to show that when the surface tension of the polymer solution is 1.5 mN/m higher than that of the condensed liquid, microsphere patterns call be prepared, whereas a honeycomb porous film of breath Figure call be obtained when the Surface tension of the polymer solution is lower than that of the condensed liquid. The viscosity of the polymer solution is also an important factor to influence the fabrication of the microsphere patterns.National Natural Science Foundation of China 2084400
Determination of Trace Metal Elements in Coastal and Estuarine Seawater by Polymer-Complexation-Ultrafiltration Technique and Inductively Coupled Plasma Mass Spectrometry
建立了高分子聚合物螯合-超滤(PCP-uf)分离富集、电感耦合等离子体质谱(ICP-MS)测定海水中痕量金属元素的方法。海水中的Cu2+,Pb2+,Cd2+,CO2+,nI2+等金属离子与聚乙烯亚胺(PEI)形成高分子螯合物,经超滤截留、酸解离后,实现金属离子从海水中定量分离、富集。ICP-MS采用全定量数据采集模式、内标校正的标准校正曲线法进行定量分析。在最佳条件下,方法的相对标准偏差(rSd)在3.4%(Cd)~9.3%(Pb)之间(0.20μg/l,n=5),标准加入回收率为78.7%(Ag)~95.2%(Cu);检出限(dl,10&)为1.2 ng/l(Cd)~9.8 ng/l(Cu),空白为1.1 ng/l(Cd,Ag)~9.1 ng/l(Cu)。本方法可应用于近岸及河口海水样品中痕量金属元素的同时测定。A method using polymer-complexation and ultrafiltration for matrix modification and inductively coupled plasma mass spectrometry(ICP-MS) for determination of trace level of metal elements(Cu2 +,Pb2 +, Cd2 +,Ni2 + and Ag +) in coastal and estuarine seawater has been developed.Full quantitative data collection mode and internal standard calibration curve were used for ICP-MS measurement.Under optimized conditions, the relative standard deviations(RSDs) were lower than 9.3%(0.20 μg/L,n = 5),and the standard added recoveries were 78.7%-95.2%.Detection limits(10 &) were from 1.2 ng/L(Cd) to 9.8 ng/L(Cu).The method blank ranged from 1.1 ng/L(Cd,Ag) to 9.1 ng/L(Cu).The developed method has been applied to simultaneously determine the metals in coastal and estuarine seawater.厦门大学近海海洋环境科学国家重点实验室自主创新项目(No.MELRI0703)资
可实现离轴反射镜离轴量精确测量的系统及方法
本发明涉及一种可实现离轴反射镜离轴量精确测量的系统及方法,该系统包括成像测量装置、立式转台、连接板、二维平移台以及光栅尺;二维平移台通过连接板设置在立式转台上并随立式转台绕立式转台的旋转轴进行旋转;待测离轴反射镜设置在二维平移台上并在二维平移台上进行二维运动;光栅尺的一端固定在连接板上,另一端止靠在平移台上;成像测量装置的光轴与立式转台的转轴是重合的。本发明提供了一种测量精度高的可实现离轴反射镜离轴量精确测量的系统及方法
科技引领创新 产业助力扶贫――杂交构树扶贫工程在山东菏泽的成效与启示
国家重大需求和社会经济发展是科技创新的方向和动力,科技创新促进经济发展、社会进步。科技创新是推动决胜脱贫攻坚的新动力。立足我国粗蛋白饲料原料进口的现状和畜牧业发展形势,中国科学院植物研究所培育出速生、丰产、优质的杂交构树新品种"科构101",提出了"以树代粮、种养循环"产业发展模式,有效解决贫困地区农户对饲料的需求,促进贫困地区畜牧业的发展。文章分析山东菏泽构树产业扶贫工作进展,探讨了构树产业扶贫面临的机遇、问题及其对策
- …
