模型药物毒性血清1H NMR谱代谢组学的Fisher判别分析研究

基于核磁共振技术的代谢组学是近年发展起来的一种新的组学技术,主要利用生物体液的核磁共振谱提供生物体内全部小分子代谢物的丰富信息。然而,噪声的存在影响了模式识别方法分析的准确度。近年来小波变换以其多分辨率分析的特性、方法简单、快速等优点成为一种有效的去除分析信号噪声的方法。本实验通过运用小波变换去除噪声、校正基线后,再进行Fisher判别分析,得到了较传统分析更为清晰的代谢标识物,建立了良好的代谢模型

利用~1H-NMR计算环化氯丁橡胶的环化度和溶剂参与量

对环化氯丁橡胶的1H -NMR谱进行了归属 ,并推导出计算环化氯丁橡胶 (CR)的环化度和溶剂参与量的公式。

长期服用硝酸镧对大鼠机体影响的~1H NMR研究

随着稀土应用的日益扩大,稀土将有可能越来越多地进入生态环境和生物体内,但其作用机理及对生物体正常生理功能的影响还不清楚,因此研究稀土的生物效应是一个迫切需要解决的重要基础课题。本文采用现代核磁共振技术,通过分析灌胃给药0．2,2．0,10,20mg/kg 剂量的 La(NO_3)_3六个月后大鼠血清中某些内源性化合物的变化研究了稀土化合物在动物体内的作用情况及长期毒性,同时对20mg/kg 剂量组三个月后大鼠尿液的 H NMR 谱图进行了分析,并通过血液中一些重要生化指标的测定对结果进行了验证。图1(a)为正常大鼠血清的 H NMR 谱,图1(b)为给药(10mg La(NO_3)_3/kg)六个月后大鼠血清的 H NMR 谱图。从图中一些内源性化合物的物种和浓度的变化可以看出,稀土在体内长期作用后,可能导致动物肝脏和肾脏物特定部位受到了一定程度的损害,并使体内酶代谢发生紊乱,且随着稀土量的增多,损害程度也越严重。另外通过20mg La(NO_3)_3/kg 组三个月后大鼠尿液的 H NMR 分析及血液中生化指标的检测结果也可得出动物机体受损的信息。本方法也可应用于非先天疾病的异常代谢的临床检测及其它药...

两种新DTPA衍生物的~1H NMR滴定研究

合成了两种新的DTPA双酰胺衍生物，DTPA－BDMA和DTPA－BDEA．通过~1HNMR滴定研究发现这两种化合物的质子解离过程为：中部胺基（PH＜0．5），端部羧基（0．5＜PH＜3．1），中部羧基（3．1＜pH＜5．4），端部胺基（5.4＜pH＜8．5）和中部胺基（8.5＜pH＜12.5）．在质子解离过程中端部胺基上的一个质子能转位到中部胺基上，同时分子结构将发生较大变化。Gd（DTPA－BDMA）和Gd（DTPA－BDEA）的弛豫效率分别为4．01和4．97L·mmol－1.s－1（400MHz，pH＝7.3，25℃），说明这两种化合物是非常有应用前景的MRI造影剂．

双甘肽稀土配合物溶液结构的~(13)C~1H NMR研究

关于双甘肽的~(13)C化学位移行为及其与稀土离子的配位作用前人有过报导。但有关水溶液中双甘肽稀土配合物的结构仍不清楚。本文测定了在重稀土离子Dy~(3+)、Ho~(3+)、Er~(3+)、Tm~(3+)和Yb~(3+)作用下双甘肽~(13)C和~1H的顺磁诱导位移,研究了水溶液中双甘肽稀土配合物的组成及结构。1 实验部分

A monometallic tri-spin single-molecule magnet based on rare earth radicals

A mononuclear tri-spin single-molecule magnet based on the rare earth radical [Tb(hfac)(3)(NITPhOEt)(2)] (NITPhOEt = 4'-ethoxy-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) has been synthesized, structurally characterized and the alternating current signals show a slow relaxation of magnetization and frequency-dependent signals.

Probing single-molecule by surface-enhanced resonance Raman scattering with linearly and circularly polarized laser

Rhodamine 6G (R6G) was incubated in silver sols with different low concentrations and its surface-enhanced resonance Raman scattering (SERRS) spectra, excited by linearly and circularly polarized light, respectively, were studied. At the single-molecule level the SERRS spectra were recorded in 10(-13) M dye colloidal solution. Spectral inhomogeneous behaviors from single-molecule were observed such as spectral polarization, spectral diffusion and intensity fluctuations of vibrational lines. Difference between SERRS spectra of R6G excited by linearly and circularly polarized light and the effect of the polarizing angle of Raman signal relative to the slit of spectrograph on the Raman spectral polarization were analyzed and measured experimentally. Circularly polarized laser and the correction of the polarizing angle of Raman signal are necessary to avoid fake results in the measuring of Raman spectral of single-molecule, which was not noticed in initial papers. (c) 2005 Elsevier B.V. All rights reserved.

Constitutive plasma membrane targeting and microdomain localization of Dok5 studied by single-molecule microscopy

In the present study, single-molecule fluorescence microscopy was used to examine the characteristics of plasma membrane targeting and microdomain localization of enhanced yellow fluorescent protein (eYFP)-tagged wild-type Dok5 and its variants in living Chinese hamster ovary (CHO) cells. We found that Dok5 can target constitutively to the plasma membrane, and the PH domain is essential for this process. Furthermore, single-molecule trajectories analysis revealed that Dok5 can constitutively partition into microdomain on the plasma membrane. Finally, the potential mechanism of microdomain localization of Dok5 was discussed. This study provided insights into the characteristics of plasma membrane targeting and microdomain localization of Dok5 in living CHO cells. (C) 2008 Elsevier B.V. All rights reserved.

Heterodimerization of integrin Mac-1 subunits studied by single-molecule imaging

Heterodimerization of integrin Mac-1 (alpha(M) beta(2)) Subunits plays important role on regulating leukocytes adhesion to extracellular matrix or endothelial cells. Here, using total internal reflection microscopy, we investigated the heterodimerization of integrin Mac-1 subunits at the single-molecule level in live cells. Individual alpha(M) subunit fused to the enhanced yellow fluorescent protein (eYFP) was imaged at the basal plasma membrane of live Chinese hamster ovary (CHO) cells. Through analysis of mean square displacement (MSD), diffusion coefficient, the size of restricted domain and fraction of molecules undergoing restricted diffusion, we found that as compared with the diffusion in the absence of beta(2) subunit, the diffusion of single-molecule of alpha(M)-YFP was suppressed significantly in the presence of beta(2) subunit. Thus, based on the oligomerization-induced trapping model, we suggested that in the presence of beta(2) subunit, the am subunit may form heterodimer with it. (C) 2008 Elsevier Inc. All rights reserved.

Single-molecule detection in a liquid by surface-enhanced resonance Raman scattering

Surface-enhanced resonance Raman scattering (SERRS) of Rhodamine 6G (R6G) adsorbed on colloidal silver clusters in a liquid has been studied. The first observation of single molecule resonance Raman scattering in a liquid in a probed volume of 10 pL was achieved. Anisotropy of SERRS spectra of single R6G molecule and huge SERRS spectra were observed and compared with that of single molecule fixed in the dried films of sols, which revealed the intricate complex interaction between R6G molecules and the environment in a liquid.