气相色谱-质谱结合主成分分析方法用于鼻咽癌病人血清中代谢产物的定性定量分析

建立了气相色谱-质谱(GC-MS)同时测定鼻咽癌患者和健康人血清样本中多种代谢物的方法。采用肟化-硅烷化的两步衍生方法,利用DB-5MS毛细管柱程序升温法分离血清中的多种成分。利用NIST标准质谱库和标准品对尿液中的代谢物进行定性定量分析,共鉴定出氨基酸、糖类、脂肪酸、有机酸和酯类等28种内源性代谢物质;进而使用主成分分析(PCA)模式识别方法分析健康人和病人血清中代谢产物差异。结果表明,该方法简便快捷,易于操作,且灵敏度高,能够同时检测血清中的多种组分,且在主成分分析下有明显的分类,因此可为鼻咽癌的早期诊断和发病机制研究提供新的策略。     

气相色谱-质谱分析血清代谢组前处理中的除蛋白及衍生方法

采用气相色谱-质谱联用技术(GC-MS),对代谢组学研究中血清样本的前处理方法进行考察,研究蛋白去除和衍生化两个步骤对血清代谢物分析的影响。对血清样本和质控(Quality control,QC)样本的图谱进行峰相对标准偏差(RSD)计算,全谱主成分分析(Principal components analysis,PCA)和信息量的计算以及代谢物的定性定量分析。结果表明,QC样本和血清平行样的峰面积RSD均小于10%,PCA分析结果及信息量计算结果都表明这些前处理方法重复性及可靠性良好,适用于代谢组学研究。4种前处理方法所得代谢图谱的PCA分析结果表明不同除蛋白试剂和衍生化试剂对代谢物谱存在不同的影响,其中衍生化试剂的影响大于除蛋白试剂的影响。信息量计算显示MSTFA组图谱的信息量(约8.9)大于BSTFA组的信息量(约8.7)。对血清样本定性共得到44种代谢物,MSTFA组血清样本特有代谢物5种,BSTFA血清样本特有代谢物6种。对定性结果进行分析后建议:当需要研究极性氨基酸和短链脂肪酸时,采用BSTFA作衍生化试剂较合适;而当需要研究非极性氨基酸和长链脂肪酸时,采用MSTFA作衍生化试剂较合适。     

气相色谱-质谱法同时测定人血浆中多种内源性代谢物

建立了气相色谱-质谱(GC-MS)法同时测定人血浆中脂肪酸、氨基酸、糖类、有机酸、酯类及胆固醇等多种内源性代谢物的方法。以十七烷酸为内标,利用甲醇除蛋白,肟化-硅烷化法衍生化来预处理样品;气相色谱-质谱测定中,采用DB-5MS毛细管柱,程序升温分离血浆中多种物质。实验获得二维数据后用直观推导式演进特征投影法(HELP)解析重叠色谱峰,用NIST质谱库和标准品共鉴定出45种内源性代谢物。结果表明方法简便、灵敏度高,已成功应用于健康人和冠心病人血浆中多种内源性代谢物的同时定性定量分析。     

基于气相色谱-质谱联用和图模型分析的脂代谢异常患者血浆代谢组学研究

利用气相色谱-质谱联用技术(GC-MS)和图模型分析方法,寻找脂代谢异常患者可能的血浆代谢标志物群。采用GC-MS技术对37例脂代谢异常患者和10例健康人的血浆样品进行分析,得到血浆代谢物的表达谱。偏最小二乘-判别分析(Partial least squares-discriminant analysis,PLS-DA)得分图可区分脂代谢异常患者与健康人,运用PLS-DA载荷图及t检验发现有9个代谢物在两组间存在显著性差异。经NIST谱库检索,它们分别为缬氨酸、甘氨酸、丙氨酸、焦谷氨酸、葡萄糖醛酸、半乳糖、甘露糖、亚油酸和甘油。在脂代谢异常患者血浆中,除甘油浓度显著高于健康人外,其余8种代谢物浓度均明显低于健康人。图模型分析结果发现这些代谢物与脂代谢异常临床常用诊断指标之间具有很好的相关性。它们可能是脂代谢异常疾病早期诊断和预后新的特异性代谢标志物群。     

叶酸及其相关代谢物在神经管畸形风险评估和预测中的作用比较研究

以叶酸及其相关代谢物为研究对象,结合定量分析方法以及多种统计学方法,比较它们在神经管畸形发病风险评估和预测中的作用。采用前期建立的HPLC-MS/MS方法测定了121例病例和118例对照母体血清中的代谢物水平,通过双样本成对t检验筛选差异代谢物(p<0.05),然后利用Logistic回归和ROC分析计算这些代谢物的优势比以及预测灵敏度及特异性、阳性和阴性预测率。结果表明,4种差异代谢物中,5-甲基四氢叶酸和同型半胱氨酸的优势比、阳性和阴性预测率均高于叶酸。本方法适用于疾病标志物的筛选和评价。     

气相色谱-质谱和液相色谱-质谱联用方法用于口腔癌代谢组学分析

口腔癌的发病率占全身恶性肿瘤的第6位,正确区分正常状态与良性和恶性口腔肿瘤,是恰当选择治疗方案的关键所在。本研究中,首先利用液相色谱-质谱和气相色谱-质谱联用方法分别得到健康人、良性口腔肿瘤患者和恶性口腔肿瘤患者血浆、尿液和唾液的代谢轮廓,然后应用正交信号校正的偏最小二乘法进行多变量统计分析。结果表明健康人、良性肿瘤患者和恶性肿瘤患者在血浆、尿液和唾液等3种体液代谢中都可以被区分开,而且找到和鉴定出19个重要差异代谢物。相关代谢通路分析显示,与健康人相比,良性和恶性口腔肿瘤患者都存在能量代谢紊乱和脂类代谢失衡的现象,但恶性口腔肿瘤患者还表现出三羧酸循环和肌醇代谢异常,这为临床诊断及治疗提供了重要信息。     

气相色谱-质谱法分析乳腺癌患者血清中的代谢物

建立了气相色谱-质谱法分析乳腺癌患者血清中代谢物的分析方法。分别收集乳腺癌患者、一般疾病者和健康对照组血清,样本用甲醇∶乙腈∶丙酮=1∶1∶1(V/V)提取,硅烷化试剂N,O-双甲氧基三氟乙酰胺+1%三甲基氯硅烷(BSTFA+1%TMCS)衍生后,采用气相色谱-质谱法分析其中的氨基酸、脂类和糖类的代谢谱,并用主成分分析(PCA)和随机森林(RF)算法对实验结果进行分析。结果表明,三组实验数据被成功分类,并发现磷酸、N-巴豆酰基甘氨酸、2,4-二羟基丁酸、棕榈酸、N-苯基甘氨酸和N-1-己酰甘氨酸等组分在乳腺癌组和健康对照组中的差异较为显著。     

基于气相色谱-质谱联用技术的痛风病人血清代谢特征分析

痛风是一组仅见于人类的异质性疾病,随着时间的推移,将导致慢性关节炎并逐渐致残。该研究将基于气相色谱-质谱联用技术(GC-MS)的代谢组学方法应用于痛风病人的血清代谢特征分析。首先利用GCMS获得痛风病人和健康人的血清代谢指纹图谱,采用多变量统计分析对所得数据进行分析。主成分分析(PCA)得分图显示,痛风病人与健康人的血清代谢谱有差异。通过偏最小二乘-判别分析(PLS-DA)对样品进行进一步分型,根据模型的变量重要性因子(VIP值)及非参数检验结果筛选差异代谢物。共筛选出43种可能与痛风相关的代谢物,并对其中22个变量进行结构鉴定,主要包括丙二醇、2,3-二羟基丁酸、2,4-二羟基丁酸、赤藓糖醇、苏糖醇、苏糖酸、阿拉伯糖醇、D-葡萄糖酸、肌醇、次黄嘌呤、尿酸、尿苷、3-羟基-3-甲基丁酸、鸟氨酸、吲哚-3-乳酸、单乙醇胺、甘油、甘油酸、月桂酸及亚油酸等代谢物。与健康人相比,痛风病人的糖代谢、核苷酸代谢、氨基酸代谢及脂类代谢均发生了明显的紊乱。这些结果将为痛风临床诊断及治疗提供重要依据。     

柱前衍生化结合LC-MS~n分析人尿中茶碱及其代谢物

采用固相萃取结合化学衍生化的样品柱前预处理方法,利用液相色谱-电喷雾/多级质谱联用技术(LC-ESI/MSn),对人经口服给药后尿液中的茶碱及其代谢产物进行分析,探讨了茶碱、代谢物及相关衍生物的质谱裂解行为,推测茶碱在人体内的代谢途径。尿样经Bond Elute C18小柱固相萃取,收集甲醇洗脱部分在50℃下氮气吹干,以N,N-二甲氨基氯乙烷为衍生试剂进行衍生化。以Shimpack C18为色谱柱、甲醇-水-甲酸(体积比20∶80∶1)为流动相,在正离子模式下对尿样中茶碱、代谢物及其衍生化产物进行LC-ESI/MSn分析。采用上述方法,共分析鉴定了人尿中的茶碱和4种代谢物(1-甲基尿酸、1,3-二甲基尿酸、1-甲基-N-乙酰化物、3-甲基黄嘌呤),其中1种代谢物未见文献报道。在正离子模式下,茶碱及代谢物的二级质谱大多丢失18 u,28 u或57 u片段生成一系列碎片离子,而衍生化产物的二级质谱均有规律地丢失45 u片段生成一系列碎片离子。通过与未经衍生化的尿样比较发现,衍生化可明显增强茶碱、1-甲基尿酸和3-甲基黄嘌呤的质谱检测灵敏度。本研究补充了茶碱在人体内的代谢轮廓,可为灵敏检测生物样本中茶碱、代谢物及其结构类似物提供借鉴。     

血浆和尿中苯并二氮杂Zhuo类药物及其代谢物的电子捕获气相色谱筛选分析法

建立了血浆和尿中11种苯并二氮杂Zhuo类药物及其9种代谢物的电子捕获检测气相色谱分析方法。血浆及加β-葡萄糖醛酸酶水解后的尿在碱性条件下用苯-异戊醇(98．5：1．5)提取，提取物非衍生化或三甲硅烷基衍生化后进行色谱分析。分析采用两根极性不同的色谱柱。检材中分析物的检出限大多数低于10μg/L，本方法还可用于定量分析。自愿者服口服治疗量药物，其血浆、尿中药物和代谢物的分析结果表明：本方法实用于麻醉抢劫案中的药物分析。     

多环芳二酐型聚酯亚胺膜的透气性能

多环芳二酐型聚酯亚胺膜的透气性能李悦生，丁孟贤，徐纪平（浙江大学高分子科学与工程研究所，杭州，３１００２７）（中国科学院长春应用化学研究所）关键词聚醚酰亚胺，聚酯酰亚胺，膜，透气性通常的聚酰亚胺加工性能较差，在芳环二酐的苯环间引入醚键等柔性基团后，其...     

Determination and study on residue and dissipation of benazolin-ethyl and quizalofop-p-ethyl in rape and soil

A QuEChERS (quick, easy, cheap, effective, rugged, and safe) method for the determination of benazolin-ethyl and quizalofop-p-ethyl in rape and soil by high-performance liquid chromatography-tandem mass spectrometry has been developed in this study. The residue and dissipation of benazolin-ethyl and quizalofop-p-ethyl in rape and soil were determined with the developed method. The half-lives of benazolin-ethyl in rape straw and soil were 3.7–5.1 days and 14.3–26.3 days, respectively. The half-lives of quizalofop-p-ethyl in rape straw and soil were 5.0-6.1 days and 0.3–9.7 days, respectively. The residue of benazolin-ethyl and quizalofop-p-ethyl in rapeseed and soil were below the detection limit (i.e., 0.5?mg?kg^?1, the maximum residue level of European Union for quizalofop-p-ethyl).     

微量元素与疾病诊断治疗的研究现状及展望

对国内外微量元素与疾病的关系及其诊断治疗的研究现状及研究动向进行了综述，包括：微量元素与地方病、癌肿、心血管病、糖尿病、眼病、神经系统病等。参考文献72篇。     

Synthesis and Optical and Redox Properties of Symmetric and Asymmetric BODIPYs

Herein, we present the synthetic route and the photophysical, electrochemical as well as laser properties of novel red‐emitting boron‐dipyrromethenes (BODIPYs) bearing arylethyne moieties. Such functionality is added along the main axis of the chromophore leading to single‐ and double‐substituted derivatives. The relationship between the dye structure and the lasing properties is studied in detail with the help of the photophysical and electrochemical properties as well as quantum mechanical simulations. The asymmetric substitution of the parent dye induces inhomogeneities in the charge distribution, which leads to an overall loss of the fluorescence capacity, mainly in polar media. Such non‐radiative deactivation processes can be softened by decreasing the electron‐donor ability of the substituent or even avoided by symmetrical substitution. Thus, grafting of the arylethyne moieties at the longitudinal axis of the indacene core results in an effective strategy to develop red‐edge BODIPYs with highly efficient and photostable laser emission.     

Ti-V基储氢合金及其氢化物的物相结构与组分优化设计

Ti-V基储氢合金在室温、常压下即可表现出良好的储氢特性,且质量储氢容量明显高于传统AB₅型储氢合金,从而在氢气的精制和回收、运输和储存及热泵等方面有较早的应用。 此外,在混合气体分离、核反应堆中处理氢的同位素、镍氢电池及燃料电池负极材料等方面也得到了广泛的研究与关注。 基于目前Ti-V基储氢合金的研究现状,概述了该类合金的优势、限制性因素(包括成因)及改性手段。 此外,为了进一步理解Ti-V基合金储氢机理、构建合金组分与储氢特性之间的对应关系,本工作重点围绕Ti-V基储氢合金及其氢化物的结构、组分优化设计展开综述,并对其未来研究方向做出展望。     

钒与糖代谢及糖尿病

微量元素钒作为生物体内必需元素，经证实有很重要的生理学功能，与机体糖代谢有十分密切的关系，且能降低糖尿病动物模型的高血糖，极有可能被开发为治疗糖尿病的药物。     

Ferrocene and ferrocenium modified clays and their styrene and EVA composites

In this work, ferrocene- and ferrocenium-containing salts were employed to modify montmorillonite. X-ray measurements show an increase in the interlayer spacing upon clay modification, which means that the larger and more organophilic cations were inserted into the gallery space of montmorillonite. Attempts to prepare nanocomposites of polystyrene and ethylene vinyl acetate copolymers lead to immiscible systems; the morphology of these systems was elucidated with TEM, XRD and cone calorimetry. The thermal stability of the composites is greater than that of the virgin polymer.     

Synthesis of Tyrosol and Hydroxytyrosol Glycofuranosides and Their Biochemical and Biological Activities in Cell-Free and Cellular Assays

Tyrosol (T) and hydroxytyrosol (HOT) and their glycosides are promising candidates for applications in functional food products or in complementary therapy. A series of phenylethanoid glycofuranosides (PEGFs) were synthesized to compare some of their biochemical and biological activities with T and HOT. The optimization of glycosylation promoted by environmentally benign basic zinc carbonate was performed to prepare HOT α-L-arabino-, β-D-apio-, and β-D-ribofuranosides. T and HOT β-D-fructofuranosides, prepared by enzymatic transfructosylation of T and HOT, were also included in the comparative study. The antioxidant capacity and DNA-protective potential of T, HOT, and PEGFs on plasmid DNA were determined using cell-free assays. The DNA-damaging potential of the studied compounds for human hepatoma HepG2 cells and their DNA-protective potential on HepG2 cells against hydrogen peroxide were evaluated using the comet assay. Experiments revealed a spectrum of different activities of the studied compounds. HOT and HOT β-D-fructofuranoside appear to be the best-performing scavengers and protectants of plasmid DNA and HepG2 cells. T and T β-D-fructofuranoside display almost zero or low scavenging/antioxidant activity and protective effects on plasmid DNA or HepG2 cells. The results imply that especially HOT β-D-fructofuranoside and β-D-apiofuranoside could be considered as prospective molecules for the subsequent design of supplements with potential in food and health protection.     

Conformations and steric and stacking interactions of trisubstituted ureas and thioureas with alkyl and phenyl groups

The monomeric ν(N—H) vibrations of various trisubstituted ureas of the R₂UPh type and -thioureas of the R₂TUPh type have been studied. The trans—out isomerism in the former and the trans—out—cis isomerism in the latter are discussed from the point of view of steric effect. The monomeric ν(N—H) vibrations of RPhUPh and RPhTUPh are also examined. The single band appearing in the spectrum of both ureas is characteristic of the cis form; this suggests the existence of phenyl—phenyl interaction (the stacking interaction proposed by Galabov et al. [10]). Behavior of ν(N—H) vibrations at several concentrations is shown to be clearly different in the three forms (trans, out and cis). The presence of the cis form is confirmed by solvent effect experiments.