Eleven new complexes of rare earths with bis-Schiff base derived from N,N'-bis[(1-phenyl-3-methyl-5-oxo-4-pyrazolinyl) alpha-furylmethylidyne] ethylenediimine ((HPM alpha FP)(2)en) were synthesized. On the basis o...Eleven new complexes of rare earths with bis-Schiff base derived from N,N'-bis[(1-phenyl-3-methyl-5-oxo-4-pyrazolinyl) alpha-furylmethylidyne] ethylenediimine ((HPM alpha FP)(2)en) were synthesized. On the basis of elemental analysis and molar conductance, a general formula of the complexes, [RE(HPM alpha FP)(2)en(NO3)(2)]NO3(RE = La, Pr, Nd, Sm, Eu, Th, Dy, Ho, Er, Yb,Y), was given. The complexes were characterized by IR, UV-visible, H-1 NMR, C-13 NMR and fluorescence. The results show that the bis-Schiff base is a quadridentate ligand and the rare earth ions exhibit coordination of eight in the complexes. The antibacterial experiments indicate that they have high antibacterial activities against S. aureus, B. subtillis, E. coli, E. carotovora, C. flaccumfaciens.展开更多
Matrix-assisted laser desorption/ionization (MALDI) is a preferred and widely used mass spectrometric technique for the analysis of macromolecules. Limited UV-LDI matrices are available for the analysis of biomolecule...Matrix-assisted laser desorption/ionization (MALDI) is a preferred and widely used mass spectrometric technique for the analysis of macromolecules. Limited UV-LDI matrices are available for the analysis of biomolecules due to the restricted structural features to serve in the laser desorption/ionization mechanism with a problem of background signals appearing in the low mass region. This paper describes the application of Schiff base derivatives of acylhydrazide and isatin as alternate UV-LDI matrices for the analysis of peptides with significantly low background signals. Thirty one compounds have been successfully employed as matrices for the analysis of low molecular weight (LMW) peptides (α-Cyano-4-hydroxycinnamic acid (HCCA), a preferred choice for peptide analysis.展开更多
目的:采用核磁共振成像及优化的基于体素形态学研究(voxel based morphometry,VBM)新技术分析未经治疗的首发精神分裂症患者的脑结构非对称性改变。方法:对符合DSM-IV精神分裂症诊断标准,同时未经药物治疗的首发精神分裂症住院患者以及...目的:采用核磁共振成像及优化的基于体素形态学研究(voxel based morphometry,VBM)新技术分析未经治疗的首发精神分裂症患者的脑结构非对称性改变。方法:对符合DSM-IV精神分裂症诊断标准,同时未经药物治疗的首发精神分裂症住院患者以及正常志愿者各20例进行核磁共振扫描脑结构成像及基于VBM的脑非对称性分析。结果:病例组较正常对照显示出明显的正常非对称性减低甚至反转的改变。正常右利手左半球优势区域如额上回、颞中回、扣带回、眶回、尾状核头以及丘脑的非对称性下降;中央后回非对称性反转;海马及海马旁回的右大于左的非对称性增加。结论:脑非对称性在未用药物治疗的首发精神分裂症患者中有明显的异常改变,提示精神分裂症患者存在原发的脑结构非对称性异常,脑非对称性紊乱的存在反映了神经异常发育与精神分裂症的发病的关联。精神分裂症患者存在的脑结构非对称性异常可能构成了精神分裂症的神经生物学表征。展开更多
基于Easley、Hvidkjaer和O’Hara的序贯交易模型与PIN(Probability of Inform ation-based Trading,基于信息的交易比率)指标对我国股市知情交易情况进行的实证分析研究结果表明:(1)我国股市信息不对称程度较高;(2)由于知情交易者利用...基于Easley、Hvidkjaer和O’Hara的序贯交易模型与PIN(Probability of Inform ation-based Trading,基于信息的交易比率)指标对我国股市知情交易情况进行的实证分析研究结果表明:(1)我国股市信息不对称程度较高;(2)由于知情交易者利用坏消息的能力有限且流动性交易水平较高,我国股市知情交易比率并不太高;(3)知情交易比率与后续期间股票收益率的负相关性,表明我国股市中市场操控型知情交易比较严重。因此,我们认为应进一步完善上市公司的信息披露制度,降低投资者之间的信息不对称程度,同时确保流动性投资者参与股市的积极性;在引入做空机制时应慎重考虑和综合权衡,避免不适当地增加流动性投资者所承担的逆向选择风险水平,降低股市的流动性供给和风险分散功能;证券市场监管部门应进一步加强对异常交易活动的监控,加大对市场操纵行为的打击力度,以确保我国证券市场的健康发展。展开更多
文摘Eleven new complexes of rare earths with bis-Schiff base derived from N,N'-bis[(1-phenyl-3-methyl-5-oxo-4-pyrazolinyl) alpha-furylmethylidyne] ethylenediimine ((HPM alpha FP)(2)en) were synthesized. On the basis of elemental analysis and molar conductance, a general formula of the complexes, [RE(HPM alpha FP)(2)en(NO3)(2)]NO3(RE = La, Pr, Nd, Sm, Eu, Th, Dy, Ho, Er, Yb,Y), was given. The complexes were characterized by IR, UV-visible, H-1 NMR, C-13 NMR and fluorescence. The results show that the bis-Schiff base is a quadridentate ligand and the rare earth ions exhibit coordination of eight in the complexes. The antibacterial experiments indicate that they have high antibacterial activities against S. aureus, B. subtillis, E. coli, E. carotovora, C. flaccumfaciens.
文摘Matrix-assisted laser desorption/ionization (MALDI) is a preferred and widely used mass spectrometric technique for the analysis of macromolecules. Limited UV-LDI matrices are available for the analysis of biomolecules due to the restricted structural features to serve in the laser desorption/ionization mechanism with a problem of background signals appearing in the low mass region. This paper describes the application of Schiff base derivatives of acylhydrazide and isatin as alternate UV-LDI matrices for the analysis of peptides with significantly low background signals. Thirty one compounds have been successfully employed as matrices for the analysis of low molecular weight (LMW) peptides (α-Cyano-4-hydroxycinnamic acid (HCCA), a preferred choice for peptide analysis.
文摘目的:采用核磁共振成像及优化的基于体素形态学研究(voxel based morphometry,VBM)新技术分析未经治疗的首发精神分裂症患者的脑结构非对称性改变。方法:对符合DSM-IV精神分裂症诊断标准,同时未经药物治疗的首发精神分裂症住院患者以及正常志愿者各20例进行核磁共振扫描脑结构成像及基于VBM的脑非对称性分析。结果:病例组较正常对照显示出明显的正常非对称性减低甚至反转的改变。正常右利手左半球优势区域如额上回、颞中回、扣带回、眶回、尾状核头以及丘脑的非对称性下降;中央后回非对称性反转;海马及海马旁回的右大于左的非对称性增加。结论:脑非对称性在未用药物治疗的首发精神分裂症患者中有明显的异常改变,提示精神分裂症患者存在原发的脑结构非对称性异常,脑非对称性紊乱的存在反映了神经异常发育与精神分裂症的发病的关联。精神分裂症患者存在的脑结构非对称性异常可能构成了精神分裂症的神经生物学表征。
文摘基于Easley、Hvidkjaer和O’Hara的序贯交易模型与PIN(Probability of Inform ation-based Trading,基于信息的交易比率)指标对我国股市知情交易情况进行的实证分析研究结果表明:(1)我国股市信息不对称程度较高;(2)由于知情交易者利用坏消息的能力有限且流动性交易水平较高,我国股市知情交易比率并不太高;(3)知情交易比率与后续期间股票收益率的负相关性,表明我国股市中市场操控型知情交易比较严重。因此,我们认为应进一步完善上市公司的信息披露制度,降低投资者之间的信息不对称程度,同时确保流动性投资者参与股市的积极性;在引入做空机制时应慎重考虑和综合权衡,避免不适当地增加流动性投资者所承担的逆向选择风险水平,降低股市的流动性供给和风险分散功能;证券市场监管部门应进一步加强对异常交易活动的监控,加大对市场操纵行为的打击力度,以确保我国证券市场的健康发展。
