Determination of Melamine in Candies by Triple Quadurupole Liquid Chromatography-Tandem Mass Spectrometry

本文建立了高效液相色谱串联质谱检测糖果中三聚氰胺的方法。以糖果为基质,采用三氯乙酸水溶液超声提取目标分析物,提取液经过离心、净化处理后,用强阳离子交换与反相C18混合填料色谱柱分离,乙腈和l0MMOl/l乙酸铵作为流动相(1:1),用串联质谱在多级反应监测模式下定量检测。lC-MS/MS定量限为0.01Mg/kg,线性范围为10~500μg/l,相关系数r2>0.99,平均回收率为66.8%~98.7%,相对标准偏差为1.9%~7.6%(n=6)。A method to analyze melamine residue in candies was established by using triple quadurupole liquid chromatography-tandem mass spectrometry(LC-MS/MS).Trichloroacetic acid was used to extract the target analyte.The CAPCELL PAK CR column was used for separation and the multiple reaction monitoring(MRM) positive ion mode was used for the determination.The limit of detection was 0.01mg/kg for LC-MS/MS.The coefficient of linear calibration curve was over 0.99 within the melamine concentration range of 10～500μg/L.The average recoveries of melamine by this method were 66.8%～98.7%,and the RSDs ranged from 1.9%～7.6%(n=6

养老机构老年人生活满意度影响因素的主成分logistic回归研究

目的分析养老机构内老年人生活满意度情况及其影响因素。方法采用整群随机抽样方法,在厦门市13家养老机构抽取230名老年人进行调查,了解养老机构老年人生活满意度状况,并利用主成分logistic回归分析其影响因素。结果获得有效问卷204份。调查显示厦门市养老机构内老年人生活满意度普遍较高。女性、年龄小、文化程度高、日常生活能力和健康自评效果好、与亲人相见频数高、对机构支持信任度高的老年人生活满意度相对较高。结论为提高养老机构老年人生活满意度,积极应对老龄化,老人应理性对待自身健康状况,积极面对生活;亲属应多去看望,给予老人更大的关爱和心理慰藉;养老机构也应大力提高其服务质量,丰富服务内容,给予老年人充分的物质、精神支持。国家自然科学基金(71403229,81573257

基于Andersen模型的“医养结合“型机构养老需求的影响因素研究

目的了解老年人对\"医养结合\"型机构养老需求的现状及其影响因素,为构建多层级、持续性\"医养结合\"长期照护服务体系提供循证依据。方法采用多阶段抽样方法,抽取厦门市6个区,16个街道/镇,44个社区,3260名60周岁及以上老年人进行面对面问卷调查。基于Andersen理论模型,采用卡方检验分析人群分布差异,采用二元logistic回归分析方法从倾向性因素、使能因素、需要因素等方面分析老年人对\"医养结合\"型机构养老需求的影响因素。结果大多数老年人选择传统的居家养老(82.01%),仅有12.89%的老年人表示希望入住\"医养结合\"型养老机构。倾向性因素中,年龄越大、文化水平越高、居住在农村的老年人更倾向于选择医养结合养老模式,OR值均大于1(P<0.05);使能因素中,在婚、主要由配偶照护、经济状况越好的老年人倾向于医养结合式养老,OR值均大于1(P<0.01);需要因素中,老年人自理情况越差越倾向于入住\"医养结合\"型养老机构(P<0.01)。使能因素对模型的贡献度最大,对医养结合养老需求的影响最大。结论厦门市老年人对于\"医养结合\"机构养老模式的需求高于一般的机构养老需求。\"...国家自然科学基金项目(81573257);;\n福建省自然科学基金(2017J01133

Unusual Boron-Carbon Compounds Containing Planar Tetracoordinate and Pentacoordinate Carbons

采用密度泛函理论(dfT),在b3lyP/6-311+g**水平上,研究了三类包含平面四配位碳原子(PTC)和平面五配位碳原子(PPC)的硼碳化合物.这三类新型化合物是由C3b2H4(包含PTC)、Cb4H2(包含PTC)和Cb5H2(包含PPC)三种稳定结构和—CHCH—单元连接起来而得到的.在理论上探讨了这些新型的硼碳化合物的成键特征,光谱性质以及芳香性.研究结果表明:包含PTC和PPC原子的能量最低的结构,在不受对称面限制的条件下,具有C2V对称性的顺式立体构型比具有反式平面构型的化合物稳定.计算的核独立化学位移(nICS)显示,这些新型化合物的三元环中心有强的芳香性.计算最稳定硼碳化合物的PTC和PPC原子的WIbErg键指数(WbIS)表明PTC和PPC的成键遵循八隅规则.Unusual boron-carbon compounds containing planar tetracoordinate carbon (ptC) and planar pentacoordinate carbon (ppC) were investigated using density functional theory (DFT) at B3LYP/6-311+G** level.These novel compounds are generally assembled with three types of stable structural units C3B2H4 with ptC, CB4H2 with ptC, and CB5H2 with ppC as well as linking elements—CHCH—.On the basis of calculation results the bonding features, spectroscopic properties, and the aromaticities of these novel boron-carbon compounds were discussed.Results show that as for the lowest-energy compounds contained ptC and ppC without being limited by symmetrical planes, stereo cis-structures of C2v symmetry are more stable than the corresponding planar trans-structures.Calculated nucleus-independent chemical shift (NICS) values show that the aromaticity of the center of the three-membered rings is the strongest.The total Wiberg bond indices (WBIs) of the ptC and ppC atoms of the most stable structures of the boron-carbon compounds indicate that the ptC and ppC obey the octal rule.supportedbytheExcellentSciencePre-researchProjectofShaanxiNormalUniversity(China)in2008---

厌氧条件在不同Fe( II) 浓度测定方法中必要性的比较研究

厌氧是目前Fe(II)测定方法中常选择的处理方式,但是不可避免会给实验操作带来不便。为了方便、准确地测定铁还原体系中的Fe(II)浓度,对比研究了厌氧条件对草酸&mdash;草酸铵和盐酸两种典型浸提方法测定Fe(II)浓度的影响。结果表明:对于草酸&mdash;草酸铵浸提法,厌氧条件是必须的,以防止提取液中的Fe(II)被氧化,而且样品浸提1 h 便可用于Fe(II)的测定;然而对于盐酸浸提法,厌氧条件却并不是必须的,对Fe(II)浓度测定基本不产生影响。因此,为简化实验操作或在没有厌氧条件的情况,可利用盐酸浸提法测定铁还原体系中Fe(II)浓度

Effect of oleoylethanolamide on expression of vascular cell adhesion molecule-1 in human umbilical vein endothelial cells

目的探讨油酰乙醇胺(OEA)对肿瘤坏死因子α(TNF-α)诱导的人脐静脉内皮细胞血管细胞黏附分子-1(VCAM-1)表达的影响。方法体外培养人脐静脉内皮细胞,分别加入3种不同浓度的OEA(10,50,100μmol/L)或非诺贝特(10,50,100μmol/L)共同孵育10 h,再加入TNF-α共同孵育6 h,采用实时定量逆转录聚合酶链式反应和酶联免疫吸附剂检测测定VCAM-1以及mRNA和蛋白的表达,并采用Western blot方法检测过氧化物酶体增殖物激活受体α(PPAR-α)的蛋白表达。结果与非诺贝特相比,不同浓度的OEA更加显著地抑制人脐静脉内皮细胞VCAM-1mRNA和蛋白的表达,随着浓度的增大,抑制作用逐渐增强。Western bolt结果显示OAE能明显增强PPAR-α蛋白的表达。结论OEA对TNF-α引起的内皮细胞受损起到保护作用,其机理可能与上调过PPAR-α有关。 【英文摘要】 Purpose To investigate the effect of oleoylethanolamide(OEA) on tumor necrosis factor α(TNF-α)induced the expression of vascular cell adhesion molecule-1(VCAM-1) in human umbilical vein endothelial cells(HUVECs).Methods OEA and fenofibrate of different concentrations were incorporated in HUVECs for 10 hours respectively.Human recombinant TNF-α was then incubated with HUVECs for 6 hours.The expression of VCAM-1 in mRNA level and protein level was detected by real-time quantitative RT-PCR and enzyme linked im...厦门大学“活性有机小分子的合成化学与化学生物学”创新团队项目;; 厦门市科技局科技计划350Z20083007项

A Study on the mechanisms of eutrophication of a shallow upstream lake in the Jiulong River Catchment

基于对九龙江上游龙潭湖富营养化水体和沉积物现状的监测结果,通过与国内富营养化深水湖库和流域下游大型富营养化浅水湖泊进行对比,深入探讨了流域上游浅水湖泊富营养化发生的原因及主导机制.流域上游浅水湖泊具有外源污染物输入较少的特点,较下游大型浅水湖泊更易受温度等气候条件和沉积物氧化还原状态的影响,以及外源输入总磷控制具有较强的滞后效应,因此对流域上游浅水湖泊富营养化的控制必须重视内源营养盐释放,特别是结合态磷的内源释放问题.Based on site monitoring chemical data of lake water and sediments during an algal bloom in the Longtan Lake,causes and mechanisms of eutrophication in shallow upstream lakes were discussed by comparing the Longtan Lake in upstream of the Jiulong River with deep eutrophic lakes and large shallow downstream eutrophic lakes in China.The shallow upstream lake is characterized as relatively simple nutrient inputs and high susceptivity to climatic variability(such as temperature),redox conditions,and strong lag effects of the external total phosphorus inputs.Therefore,attention must be paid to the sediments nutrient releases,especially,the bound phosphorus of sediments when remediating eutrophication in shallow upstream lakes.国家自然科学基金资助项目(41175130);教育部新世纪优秀人才支持计

死亡受体5胞外区域的重组、表达及活性鉴定

目的构建死亡受体5(deathreceptor5,DR5)胞外区域(eDR5)的表达载体,表达纯化重组蛋白并鉴定其生物特性。方法通过重叠PCR获得DR5胞外段编码序列,构建pET-22b(+)/DR5表达载体,转化大肠杆菌BL21(DE3),IPTG诱导表达,Ni2+柱亲和纯化,SDS-PAGE、直接ELISA鉴定纯化产物的纯度和特异性,用MTT法检测eDR5蛋白阻断DR5单克隆抗体FMU1.5和TRAIL诱导人胶质瘤细胞株U343(高表达DR5)、U373(低表达DR5)细胞凋亡的作用。结果获得了DR5胞外段编码序列,目的蛋白在上清及包涵体中都有表达,表达量占菌体总蛋白的30%以上,纯化的重组蛋白纯度达95%以上,蛋白产量达9mg/ml。ELISA结果表明所纯化蛋白为eDR5。eDR5蛋白可部分阻断FMU1.5和TRAIL诱导人胶质瘤细胞株U343细胞凋亡的作用,其阻断率与DR5表达相关。结论死亡受体5胞外段基因的成功重组、表达及纯化,为进一步的功能研究奠定了基础

人死亡受体5全长基因的构建及转染胶质瘤细胞

目的构建人死亡受体5(death receptor5,DR5)全长基因真核细胞表达载体pcDNA3.1/DR5,pcDNA3.1/GFP/DR5,并观察其转染胶质瘤细胞U138的效果。方法通过重叠PCR获得DR5全长编码序列,构建pcDNA3.1/GFP/DR5,pcDNA3.1/DR5表达载体,利用脂质体转染试剂盒,分别将2种质粒pcDNA3.1/GFP/DR5、pcDNA3.1/GFP共转染胶质瘤细胞U138,转染后72h,半定量逆转录聚合酶链反应(RT-PCR)检测DR5mRNA的表达,流式细胞术检测DR5的表达强度、检测Anti-DR5对胶质瘤细胞U138生长的影响。结果获得了DR5全长编码序列,成功瞬时转染U138,RT-PCR、流式细胞术检测结果表明,转染后U138细胞DR5mRNA、蛋白水平的表达明显增加,Anti-DR5可以明显抑制U138细胞的生长。结论获得了DR5全长编码序列,探索到成功转染DR5的最佳方法,为稳定筛选高表达DR5的U138细胞提供依据